Price  50  cents 


REPRINT  AND  CIRCULAR  SERIES 

OF  THE 

NATIONAL  RESEARCH 
COUNCIL 


RESEARCHES  ON  MODERN  BRISANT  NITRO  EXPLOSIVES 
BY  C.  F.  VAN  DUIN  AND  B.  C.  ROUTERS  VAN  LENNEP 


TRANSLATED  BY  CHARLES  E.  MUNROE 

Chairman,  Committee  on  Explosives  Investigations,  Division  of 

Chemistry  and  Chemical  Technology,  National 

Research  Council 


™^^^^M 

California 
Regional 
'acility 


Published  in  Recueil  des  Travaux  Chimiques  des  Pays-Bas 
February  15,  1920,  vol.  39,  no.  2,  pp.  145-177 


Announcement  Concerning  Publications 

of  the 
National  Research  Council 


The  Proceedings  of  the  National  Academy  of  Sciences 

has  been  designated  as  the  official  organ  of  the  National  Research 
Council  for  the  publication  of  accounts  of  research,  committee  and 
other  reports,  and  minutes. 

Subscription  rate  for  the  "Proceedings"  is  $5  per  year.  Business 
address:  Home  Secretary,  National  Academy  of  Sciences,  Smith- 
sonian Institution,  Washington,  D.  C. 

The  Bulletin  of  the  National  Research  Council 

presents  contributions  from  the  National  Research  Council,  other 
than  proceedings,  for  which  hitherto  no  appropriate  agencies  of 
publication  have  existed. 

The  "Bulletin"  is  published  at  irregular  intervals.  The  sub- 
scription price,  postpaid,  is  $5  per  volume  of  approximately  500 
pages.  Numbers  of  the  "Bulletin"  are  sold  separately  at  prices 
based  upon  the  cost  of  manufacture  (for  list  of  bulletins  see  third 
cover  page). 

The  Reprint  and  Circular  Series  of  the  National  Research 

Council 

renders  available  for  purchase,  at  prices  dependent  upon  the  cost 
of  manufacture,  papers  published  or  printed  by  or  for  the  National 
Research  Council  (for  list  of  reprints  and  circulars  see  third  cover 
page). 

Orders  for  the  "Bulletin"  or  the  "Reprints  and  Circulars"  of  the 
National  Research  Council,  accompanied  by  remittance,  should  be 
addressed:  Publication  Office,  National  Research  Council,  1701 
Massachusetts  Avenue,  Washington,  D.  C. 


REPRINT  AND  CIRCULAR  SERIES 

OF  THE 

NATIONAL  RESEARCH  COUNCIL 

NUMBER  15 


RESEARCHES  ON  MODERN  BRISANT  NITRO 
EXPLOSIVES* 

BY   C.   F.    VAN    DUIN   AND   B.    C.    ROETERS   VAN   LENNEP 

Translated  by  CHARLES  E.  MUNROE 

Chairman,  Committee  on  Explosives  Investigations,  Division  of  Chemistry  and  Chemi- 
cal Technology,  National  Research  Council 

INTRODUCTION 

In  the  examination  of  explosives  there  are  actually  established 
the  following  constants  according  to  the  methods  developed  by 
Bichel,1  Kast,2Will,  Dautriche,  Noble,  etc.,  and  to  the  principles 
enunciated  by  Berthelot,3  Sarrau,  Vieille,  Abel  and  others: 

1.  Velocity  or  rate  of  explosion 

2.  Energy  liberated  by  the  explosion 

3.  Composition  of  the  products  formed 

4.  Calculated  temperature  produced  by  the  explosion 

5.  Pressure  in  a  15  1.  Bichel4  bomb 

6.  Enlargement  of  the  cavity  in  a  Trauzl  lead  block 

7.  Duration  and  length  of  the  flame  produced  by  the  explosion 

of  100  g.  of  the  substance 

8.  Stability  and  the  initiating  explosion  temperature 

9.  Sensibility  to  shock 

The  greatest  weight  ought  undoubtedly  to  be  assigned  to  the 
constants  1,  2,  3,  8  and  9 ;  but  as  we  have  not  had  at  our  disposal  the 
necessary  devices  with  which  to  measure  the  first  three,  we  have 

*  From  Recueil  des  Travaux  Chimiques  des  Pays-Bas,  vol.  39,  no.  2,  pp.  145-177, 
Feb.  15,  1920. 

1  Bichel,  "Methoden  und  Apparate  der  Sprengstoff  A.  G.  Carbonit,  zur  Priifung  von 
Sprengstoffen . " 

2  Kast,  "Anleitung  zur  chemischen  und  physikalischen  Untersuchung  der  Spreng- 
und  Ziindstoffe,"  Braunschweig,  1909. 

3  Berthelot,  "Sur  la  force  des  matieres  explosives  d'apres  la  thermochimie,"  Paris, 
1883. 

4  Bichel,  Zeitschr.f.  d.  ges.  Schiess-  und  Sprengstoffiv.,  3,  365  (1901). 


2          BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP 

been  limited  to  the  determination  of  the  stability  and  of  the  sensi- 
tiveness to  shocks.  The  two  last  properties  have  had  a  special 
significance  since  Fliirscheim1  introduced  into  the  technique  of 
explosives  substances  having  very  mobile  nitro  groups,  such  as 
tetranitroaniline,  while  others  have  sought  to  employ  the  dini- 
tramines.2 

To  render  the  researches  on  strongly  nitrated  compounds  having 
one  or  more  methylnitroamino  groups  or  very  mobile  nitro  groups 
as  complete  as  possible,  we  have  also  sought  to  derive  from  the 
tetranitrophenylmethylnitramine,  2,4,6,2',3',4'-hexanitrodiphenyl- 
amine  and  tetranitrophenol  some  of  those  bodies  which  have  not 
been  employed  as  explosives  because  of  their  mode  of  prepara- 
tion or  their  properties. 

PREPARATION  AND  PROPERTIES 

I.  Tetranitrophenylmethylnitramine  (Tetryl) 


On  the  subject  of  this  explosive  one  should  consult 
existing  works.3 

N02 

II.  2,3,4,6-Tetranitroaniline 

To  the  communications  which  we  have  already  made4  on  the 
subject  of  the  preparation  and  the  properties  of  this  compound, 
we  now  add  the  results  of  the  study  of  the  action  of  moist  acetone 
upon  it,  in  which  we  have  identified  the  products  formed  in  this 
reaction.     By  the  action  of  moist  acetone  on  the  tetranitroaniline 
NH         there  are  formed  large  quantities  of  hydrogen  cyanide, 
together  with  the  trinitroamidophenol  previously  men- 
tioned.    By    distillation    in    a   vacuum   on   the   water 
bath,  after  having  eliminated  the  acetone,  there  is  ob- 
tained an  acid  liquid,  which  after  neutralization  with 
ammonia   is   colored   black   on   warming   after   the   addition   of  a 
silver  salt.5     We  expected  to  find  formic  acid  present,  but  have 

1  D.  R.  P.  241,697  and  243,079. 

2  Brevet  francais,  391,107. 

3  Van  Uuin,  Rec.  trav.  (him.,  37,  111  (1917). 

4  Van  Duin,  loc.  cit.,  114. 

5  This  distillation  ought  to  be  conducted  with  great  care,  for  there  remains  in  the 
flask  very  impure  trinitroamidophenol,  which  can  give  rise  to  an  explosion.     See  the 
experience  of  Van  Romburgh  on  the  trinitromethylnitraminophenol.     Van  Romburgh, 
Versl.  Kon.  Akad.  van  Wetensch.  Amsterdam,  23,  1340  (1915). 


BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP         3 

been  unable  to  identify  it  in  the  products  of  the  reaction.  Apart 
from  the  water,  which  is  a  most  important  fraction,  the  distilled 
liquid  appears  to  be  composed  as  follows: 

a.  Formaldehyde. — This  can  be  shown  by  a  direct  reduction  of 
a  solution  of  ammoniacal  silver  oxide  and  also  of  a  dilute  solution 
of  potassium  permanganate.     It  produced  also  an  intense  red  color, 
characteristic  of  formaldehyde,  when  the  liquid  was  mixed  with  a 
solution  of  0.1  g.  of  morphine  hydrochloride  in  5  cc.  of  concentrated 
sulphuric  acid.1 

b.  Acetic  acid. — After  neutralization  with  soda  the  liquid  was 
evaporated  and  the  salt  obtained  identified  as  sodium  acetate,  as 
follows:  ferric  chloride  produced  a  red  color  and  on  boiling  there 
was  formed  a  precipitate  of  basic  ferric  acetate.     On  heating  with 
alcohol  and  some  drops  of  concentrated  sulphuric  acid,  the  odor 
of  ethyl  acetate  was  immediately  perceived.     On  heating  with  a 
solution  of  ^-nitrobenzyl  bromide  in  63%  alcohol  as  indicated  by 
Emmet  Reid,2  crystals  were  obtained  which  fused  at  78°;  when 
these  were  mixed  with  ^-nitrobenzyl  acetate,  prepared  according 
to  the  method  described  by  the  same  author,  there  was  no  lowering 
of  the  melting  point. 

It  was  possible  to  show  the  presence  of  oxalic  acid  in  the  residue 
remaining  in  the  flask.  For  this  purpose  the  residue  was  extracted 
with  hot  water,  neutralized  by  ammonia,  and  then  acidified  by 
acetic  acid.  On  addition  of  a  solution  of  calcium  chloride 
there  was  observed  the  formation  of  a  precipitate  which  immedi- 
ately, when  warm,  reduced  the  solution  of  permanganate  of 
potash  slightly  acidified  by  sulphuric  acid.  Thus  products  formed 
in  the  decomposition  of  aqueous  solutions  of  di-isonitroso  and 
isonitroso  acetone  were  indicated,  though  we  were  not  able  to 
isolate  them. 

It  is  already  known  that  when  an  aqueous  solution  of  di-isonitroso 
acetone  is  heated,  it  decomposes  as  follows: 

H          o          H 
/        /        / 

-C >  CO2  +  2HCN  +  H2O 

\ 
NOH 

At  the  same  time  there  is  produced  a  little  ammonia,  hydrogen 
cyanide  and  oxalic  acid  :3 

1  Tendler  and  Manninck,  Zeitsch.  f.  anal.  Chem.,  48,  310  (1909). 

2  Emmet  Reid,  Journ.  Amer.  Chem.  Soc.,  39,  124  (1917). 

a  Von  Pechmann  and  Wehsarg,  Ber.  d.  deutsch.  chem.  Ges.,  21,  2989  (1888). 


BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP 


COO  NH4  —  COOH  +  HCN 


For  the  isonitroso  acetone  we  have  found  that  when  this  body  is 
heated  to  140°  in  the  presence  of  dilute  hydrochloric  acid,  it  de- 
composes as  follows:1 

OH  HO        CH3   o 


CH3  —  C  —  C  +  2H2O  -  *•  NH3  +  C  —  OH  +  C  —  OH 

\ 

NOH 

However,  given  the  low  temperature  at  which  the  action  of  moist 
acetone  on  tetranitroaniline  occurs,  the  reaction  can  be  accurately 
represented  as  follows: 

OH  H  CH3 

/    /  II 

CH3  —  C  —  C  +  2H2O  —  >  NH2OH  +  C  =  O  +  C  —  O 

\  \  \ 

NOH  H  OH 

This  is  why  it  appears,  in  accordance  with  the  facts  cited  above, 
that  the  acid  reaction  of  the  distillate  obtained  by  Van  Romburgh, 
through  the  action  of  moist  methyl  ethyl  ketone  on  tetranitro- 
phenylmethylnitramine,  should  be  attributed  to  the  presence  of 
acetic  acid,  and  its  reducing  property  to  the  presence  of  acet  alde- 
hyde. These  compounds  then  appear  to  be  produced  from  isonitro- 
somethylethylketone,  as  follows: 
CH3 

C  =  NOH  ^O 

I  +  2H2O  -  >  CHjCOOH  +  CHsCf       +  NH2OH 

c  =  o  NH 

CH3 

It  may  be  considered  established  that  Fliirscheim  was  the  first  to 
knowingly  prepare  the  tetranitroaniline.  However,  we  believe 
that  Witt  and  Witte2  have  had  this  substance  in  hand  and  have 
considered  it  as  a  trinitroaniline.  These  authors  state  that  they 
obtained  the  3,4-dinitroacetanilide,3  melting  point  144°,  when  a 

1  Treadwell  and  Steiger,  Ber.  d.  deutsch.  chem.  Ges.,  15,  1059  (1882). 

2  Witt  and  Witte,  Ibid.,  41,  3095  (1908);  see  also  Fliirscheim, 
D.  R.  P.  243,079. 

3  Wender,  Gaz.  chim.  ital,  19,  225  (1889). 


BRISA  NT  NITRO  EXPLOSI  VES:  VAN  D  UIN  AND  VAN  LENNEP         5 

solution  of  10  parts  of  m-nitroacetanilide  in  100  of  100%  sulphuric 
acid  was  mixed  below  —  5°,  with  a  solution  of  15  parts  of  dry  potas- 
sium nitrate  in  100  of  100%  sulphuric  acid  and  the  whole  allowed 
to  remain  at  the  ordinary  temperature  during  24  hours. 

It  is  alleged  that  with  longer  standing  there  is  formed,  little  by 
little,  trinitroaniline.  The  authors  have  not  given  the  fusion  point 
or  made  other  tests  but  they  note  that  an  analysis  for  nitrogen 
gave  results  corresponding  with  the  calculated  value  for  the  trinitro- 
aniline. If,  however,  we  consider  that  the  nitrogen  contents  of 
tri-  and  of  tetranitroanilines  differ  but  little  (24.56%  and  25.65%) 
one  may  realize  that  an  examination  of  impure  tetranitroaniline 
could  lead  one  to  believe  it  to  have  the  composition  of  the  trinitro 
product. 

We  have  sought  to  prepare  the  trinitroaniline  by  the  method 
described  by  Witt  and  Witte  and,  while  we  have  carefully  endeavored 
to  follow  the  instructions  given,  we  have  never  obtained  trinitro- 
aniline but  always  the  tetranitro  compound.  This  was  identified 
not  only  by  the  fact  that  it  had  the  same  melting  point  and  that 
when  mixed  with  this  substance  the  melting  point  was  not  lowered, 
but  also  because  on  boiling  in  the  presence  of  moist  acetone  it  gave 
2,4,6-trinitroamidophenol.  It  may  also  be  remarked  here  that  by 
this  process  a  very  pure  tetranitroaniline  is  immediately  obtained. 

III.  Acetyltetranitroaniline 
H      O 

/     ^ 
N  —  CCH3 

NO2         lNO2 


NO2 

We  prepared  this  body  according  to  Fliirscheim1  by  heating  pure 
tetranitroaniline  with  acetic  anhydride  and  a  little  sulphuric  acid 
at  a  temperature  not  above  80°.  After  crystallization  in  glacial 
acetic  acid  the  tetranitroaniline  fuses,  with  decomposition,  at  169- 
170  °,  cor, 

IV.  2,4,6-Trinitroamidophenol 
NH2 


NO 


NO2 

1  Flurscheim,  D.  R.  P.  241,697,  Chem.  Zentr.  Bl.,  1,  184  (1912)  ;  see  also  Witt  and  Witte, 
oc.  cit.,  for  the  preparation  of  acetylpicramide. 


6          B  RISA  NT  NITRO  EXPLOSI  VES:  VAN  D  UIN  AND  VAN  LENNEP 

Fliirscheim1  has  demonstrated  that  tetranitroaniline  can  easily  be 
transformed  into  trinitroamidophenol,  even  at  the  ordinary  tem- 
perature, if  there  is  added  to  the  acetone  solution  of  it  an  aqueous 
solution  of  sodium  acetate.  As  we  have  previously  shown,  apropos 
of  tetranitroaniline,  because  of  water  being  present  with  the  acetone 
as  well  as  sodium  acetate,  the  alkaline  reaction  of  this  latter  ought 
to  accelerate  the  transformation.  We  always  prepare  the  trinitro- 
amidophenol by  dissolving  100  g.  of  tetranitroaniline  in  600  cc.  of 
acetone  with  the  addition  of  a  little  water.  As  soon  as  the  tetra- 
nitro  compound  is  dissolved,  we  distil  off  the  acetone  until  the  tetra- 
nitrophenol  crystallizes  out;  this  is  then  dried,  washed  with  cold 
alcohol  and  then  recrystallized,  at  first  from  alcohol  and  then  from 
benzene.  Melting  point  178-179°,  cor. 

V.  2,4,6-Trinitroamidoanisol 
NH2 


OCH3 
NO2 

This  product  has  also  been  prepared  (following  Fliirscheim)  by 
boiling  crude  tetranitroaniline  with  absolute  methyl  alcohol.  The 
compound  obtained  is  twice  crystallized  from  methyl  alcohol.  To 
obtain  a  pure  product  it  is  indispensable  that  the  alcohol  be  absolute. 
Melting  point  131°,  cor. 

VI.  2,4,6-Trinitroamidophenetol 
NH2 


OC2H5 
NO2 

The  method  of  preparation  of  this  substance  is  similar  to  that  °f 
the  trinitroamidoanisol,  except  that  ethyl  alcohol  is  used.  We 
have,  however,  noticed  that  when  prepared  by  the  use  of  impure 
tetranitroaniline  very  little  of  the  trinitroamidophenetol  is  obtained, 
and  that  that  which  is  formed  is  also  impure.  The  product  is 
strongly  contaminated  by  a  fibrous  compound  which,  can  be  elimi- 
nated by  crystallization  in  alcohol-acetone;2  but  then  the  trinitro- 

1  Fliirscheim,  D.  R.  P.,  243,079,  Chem.  Zenlr.  Bl,  1,  620  (1912);  Proc.  Chem.  Soc. 
London,  26,  81. 

2  Many  compounds  studied  by  us  could  be  obtained  pure  with  facility  by  dissolving 
in  warm  acetone,  then  precipitating  the  compound  by  the  addition  of  cold  alcohol;  we 
employ  for  this  procedure  the  simplified  designation  "cristallisation  dans  I'alcool-acelone." 


BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEf         7 

amidophenetol  is  contaminated  by  trinitroamidophenol,  which  is 
difficult  to  eliminate  by  crystallization.1  While  the  purification  of 
tetranitroaniline  by  crystallization  from  glacial  acetic  acid  is  some- 
what laborious,  we  recommend  with  some  insistence  the  employ- 
ment of  the  recrystallized  product  in  the  preparation  of  the  trinitro- 
amidophenetol.  Melting  point,  107°,  cor. 

VII.  2,4,6-Trinitrometaphenylenediamine 


N 


NO2 


This  compound  was  prepared  by  Nolting  and  Collin2  from  diethyl 
ether,  styphnic  acid  and  ammonia  in  absolute  alcohol.  They  have 
described  the  compound  as  being  yellow,  crystalline,  and  fusing 
only  at  a  high  temperature.  Barr3  proceeded  as  Nolting  and  Collin 
did;  he  described  the  compound  as  yellow,  fusing  above  250°. 
Blanksma4  prepared  the  body  from  1,3, 2,4,6, -oxymethylchlortri- 
nitrobenzene,  but  he  does  not  state  either  the  color  or  the  melting 
point.  Meisenheimer  and  Patzig5  obtained  the  compound  by  the 
action  of  hydroxylamine  on  an  alkaline  alcoholic  solution  of  sym- 
metric trinitrobenzene ;  the  product  principally  formed  was  picram- 
ide.  Korner  and  Contardi6  employed  2,4,6-trinitrodibrom  and 
dichlor  benzenes  with  alcoholic  ammonia.  They  obtained  yellow 
needles  fusing  above  250°.  Fliirscheim7  employed  tetranitroaniline 
and  ammonia;  melting  point,  275°.  Van  Romburgh  and  Schepers,8 
by  the  prolonged  action  of  a  nearly  saturated  aqueous  solution  of 
ammonia  on  2,3,4,6-tetranitrophenylmethylnitramine,  obtained  the 
trinitrometaphenylenediamine  as  a  yellow-brown  product  fusing 
above  270°. 

In  our  researches  on  the  substitution  of  the  methylnitroamino 
group,9  in  the  derivatives  of  tetranitrophenylmethylnitramine,  we 

1  Van  Duin,  Rec.  trav.  chim.,  38,  89  (1919). 

2  Nolting  and  Collin,  Ber.  d.  deutsch.  chem.  Ges.,  17,  260  (1884). 
s  Barr,  Ibid.,  21,  1546  (1888). 

4  Blanksma,  Rec.  trav.  chim.,  21,  324  (1902). 

5  Meisenheimer  and  Patzig,  Ber.  d.  deutsch.  chem.  Ges.,  39,  2533  (1906). 

6  Korner  and  Contardi,  Atti  R.  Accad.  dei.  Lincei   Roma,  5,  17,  1,  465   (1908);  5,  18 
1,  93  (1909);  Chem.  Zentr.  Bl.,  1908,  II,  47;  1909,  I,  1157. 

7  Fliirscheim,  loc.  cit. 

8  Van  Romburgh  and  Schepers,   Versl.  Konin.  Akad.  van  Wetensch.  Amsterdam,  22, 
293  (1913);  Schepers,  "Dissertatie,"  Utrecht,  1913,  41. 

9  Van  Duin,  Rec.  trav.  chim.,  38,  89  (1919). 


8          RRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP 

have  obtained  the  trinitrometaphenylenediamine  by  the  action  of  a 
concentrated  ammoniacal  solution  of  2,4,6-trinitroanilidophenyl- 
methylnitramine.  The  product  is  dark  brown  and  has  a  melting 
point  of  295°,  cor.  (after  250°,  10°  per  minute).  After  crystalli- 
zation in  glacial  acetic  acid,  the  melting  point  is  raised  to  301  °,  cor. 
(after  250°,  10°  per  minute). 

We  have  also  obtained  this  product  by  the  action  of  ammonia 
on  the  2,4,6-trinitrodimethylaminophenylmethylnitramine;  the 
compound  was  dark  brown  and  with  a  melting  point  of  290  °,  cor. 
After  crystallization  in  glacial  acetic  acid  it  rose  to  296°,  cor. 
(here  also  after  250°,  10°  per  minute).  In  both  cases  the  color  of 
the  product  was  darkened  by  recrystallization. 

We  have  obtained  the  purest  trinitrometaphenylenediamine  by 
replacing  a  halogen  atom  or  an  oxyalkyl  group  by  an  amino  group, 
which  has  been  achieved  by  the  action  of  ammonia  on  trinitro- 
amido-anisol  and  -phenetol.  That  an  oxyalkyl  group,  placed  near 
a  similar  analogue,  can  be  easily  replaced  by  ammonia  has  been 
already  shown  in  the  case  of  the  isobutylic  ether  of  the  trinitro- 
methylnitraminophenol.1  Other  examples  show  that  this  replace- 
ment is  general  for  the  ethers  of  trinitroamidophenol  and  trinitro- 
methylnitraminophenol.  In  this  last  case  only  has  there  been 
obtained,  by  very  prolonged  action,  the  aminotrinitrophenylmethyl- 
nitramine,  on  the  side,  which  imparts  a  more  or  less  dark  brown 
color  to  the  trinitrometaphenylenediamine.  For  the  preparation 
of  the  trinitrometaphenylenediamine  there  is  poured  on  10  g.  of 
pure  and  finely  pulverized  trinitroamidoanisol  or  phenetol  80  cc. 
of  a  concentrated  aqueous  solution  of  ammonia  (s.  p.  0.90)  and  the 
whole  left  standing  for  24  hours  at  ordinary  temperature  with  fre- 
quent agitation;  at  the  end  of  this  time  the  reaction  is  complete. 
The  product  formed  is  filtered,  freed  from  ammonia  by  washing, 
and  boiled  with  alcohol  in  order  to  finally  eliminate  all  traces  of  the 
anisol  or  phenetol  which  have  escaped  attack.  The  melting  point 
is  then  about  285°,  cor.  After  crystallization  from  glacial  acetic 
acid  it  is  287-288°,  cor.  (after  250°,  10°  per  minute).  There  is 
thus  obtained  a  trinitrometaphenylenediamine  in  beautiful  yellow 
crystals  with  metallic  luster. 

1  Van  Duin,  Koll.  Zeitschr.,  17,  123  (1915).  The  action  of  a  concentrated  ammoniacal 
solution  of  the  ethers  of  trinitroamidophenol  and  trinitromethylnitroaminophenol  en- 
ables us  to  prepare  the  corresponding  alcohols  very  pure,  which  is  quite  important  since 
easily  accessible  alcohols  do  not  give  crystallizable  ethers  and  they  react  with  tetra- 
nitroaniline  or  tetranitrophenylmethylnitramine  to  give  the  ether  oxides.  See  Van 
Romburgh  and  Schepers,  loc.  cit. 


BRISA  NT  NITRO  EXPLOSI  VES:  VAN  D  UIN  AND  VAN  LENNEP         9 

NITROGEN  DETERMINATION 

0.1342  g.  of  the  product  gave  33.1  cc.  of  nitrogen  at  17°  and  768  mm. 

Nitrogen  found:     28.78%. 

Nitrogen  calculated  for  the  trinitrometaphenylenediamine  :     28.82%. 

In  general  it  may  be  said  that  this  trinitrometaphenylenediamine 
is  obtained  of  a  more  or  less  dark  color  when  one  or  two  amino 
groups  are  introduced  into  the  molecule  by  means  of  the  deriva- 
tives of  the  methylnitroamino  group.  It  is  remarkable  that  the 
melting  point  is  higher  for  the  impure  compounds  ;  in  addition,  the 
recrystallization  of  the  impure  compound  increases  the  melting 
point  and  at  the  same  time  darkens  the  coloration;  it  is  necessary 
then  to  use  glacial  acetic  acid  for  the  recrystallization.  The  pure 
product  commences  to  melt  without  decomposition  at  287-288°, 
cor.  (after  250°,  10°  per  minute)  ;  shortly  after  fusion  small  gaseous 
bubbles  appear  in  the  clear  yellow  liquid  ;  this  marks  the  com- 
mencement of  the  decomposition. 

It  may  be  said  that  the  impure  product  having  a  more  elevated 
melting  point  and  at  the  same  time  a  dark  coloration,  may  be  com- 
pared with  that  which  has  been  observed  for  the  trinitroamido- 
phenol  obtained  by  replacement  of  the  methylnitramino  group  in 
the  trinitromethylnitraminophenol  by  the  action  of  ammonia1  and 
removal  of  the  ammoniacal  salt.  The  trinitroamidophenol  is  brown 
and  melts  at  181°,  cor.,  instead  of  178-179°,  cor. 

VIII-XII.     2,3,4,6-Tetranitrophenylnitramine  and  its  derivatives 
CHS  CHS  CH3 

/  /  / 

N  —  NO,  N  —  NO2  N  —  NO2 

NO/^NOa  NO2f\NO2  NO/  \N02 

1       JN02  \/°H  I      JOCHs 

NO2  N02  NO2 

CH3 

/ 
N  —  NO2 


oc2H5  NH, 

NO2  NO2 

In  the  preparation  of  these  bodies,  we  have  followed  precisely  the 
directions  given  by  Van  Romburgh  and  Schepers.2     The  tetranitro- 

1  Van  Duin,  Rec.  trav.  chim.,  38,  89  (1919). 

2  Van  Romburgh,  Ibid.,  8,  273   (1889);  Van  Romburgh  and  Scheper,    Versl.  Kon. 
Akad.  v.   Wetensch.  Amsterdam,  22,  293  (1913);  Schepers,  "Dissertatie,"  Utrecht,1913. 


10        BRISA  NT  NITRO  EXPLOSI  VES:  VAN  D  UIN  AND  VAN  LENNEP 

phenylmethylnitramine  such  as  we  have  used  for  other  experiments 
was  purified  by  dissolving  in  warm  nitric  acid,  sp.  gr.  1.49,  to  which 
we  have  added  a  little  concentrated  sulphuric  acid,  in  order  to 
protect  the  nitro  group  in  position  3;1  then,  after  filtration,  we 
have  precipitated  the  compound  with  sulphuric  acid  and  have 
recrystallized  in  benzene  and  dried  with  phosphoric  anhydride. 
Melting  point,  146-147°,  cor. 

The  trinitromethylnitraminophenol2  was  obtained  by  placing  the 
crystallized  nitramine  in  a  mixture  of  sulphuric  and  nitric  acid  and 
heating  these  with  water  until  solution  was  complete.  This  phenol 
was  then  precipitated  from  the  solution  by  chlorhydric  acid,  filtered, 
dried  in  a  desiccator  over  soda  and  then  recrystallized  in  benzene. 
Melting  point,  183°,  cor. 

The  trinitromethylnitramino-anisol3  and  -phenetol4  were  pre- 
pared by  boiling  the  crude  nitramine  with  absolute  methyl  or  ethyl 
alcohols  and  then  by  recrystallization  with  these  alcohols.  Melting 
points:  anisol,  96-97°,  cor.;  phenetol,  98-99°,  cor.  It  is  to  be  re- 
marked that  the  action  of  these  alcohols  when  cold  is  much  more 
rapid  with  the  nitramine  than  with  tetranitroaniline  and  this  shows 
that  there  is  a  much  greater  mobility  of  the  nitro  group  in  the  3 
position;  this  is  in  accordance  with  the  results  of  the  tests  for  sta 
bility. 

For  the  preparation  of  the  aminotrinitrophenylmethylnitramine 
we  have  followed  the  method  of  Schepers5  but  have  operated  as 
follows  :  140  g.  of  tetranitrophenylmethylnitramine  were  introduced 
little  by  little  into  400  cc.  of  a  10%  aqueous  ammoniacal  solution 
during  which  the  reaction  vessel  was  cooled  with  cold  water.  After 
allowing  the  reaction  to  take  place  for  one  hour,  the  mixture  was 
poured  into  400  cc.  of  a  10%  chlorhydric  acid  and  then  the  amino- 
trinitrophenylmethylnitramine  formed  was  filtered.  Yield,  120  g. 

XIII.     2)4,6,3',4',6'-Hexanitrodiphenylether 
NO2  NO2 


NO2  NO2 

1  Van  Romburgh  and  Schepers,  he.  cit. 
*  Ibid. 

3  Ibid. 

4  Ibid. 

6  Schepers,  loc.  cit.,  39;  this  method  requires  much  time  for  the  preparation  o    large 
quantities;  our  preparation  is  analogous  to  it. 


BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP        1 1 

To  purify  the  product  it  was  at  first  boiled  with  alcohol  and  then 
crystallized  from  alcohol-acetone.     Melting  point,  188°,  cor. 

According  to  the  patent  of  the  Westphalisch-Anhaltische  Sprengs- 
toff  A.  G.1  the  above  compound  was  prepared  from  the  di-,  tri-, 
tetra-  and  pentanitrodiphenylethers,  which  had  a  nitro  group  in 
one  of  the  benzene  nuclei  in  the  3  position.  As  a  point  of  depart- 
ure we  found  it  best  to  take  the  nitrodiphenylether  which  could  be 
most  easily  obtained  from  2,4-dinitrochlorobenzene  or  picryl  chloride 
and  the  w-nitrophenol.  We  have  always  made  use  of  the  2,4,6,3'- 
tetranitrodiphenylether  which  can  easily  be  prepared  by  following 
the  instructions  of  the  patent.2  There  is  thus  obtained  a  com- 
pound which  melts  at  172°,  cor.,  after  recrystallization  from  glacial 
acetic  acid.  This  tetranitrodiphenylether  can  be  easily  trans- 
formed into  2,4,6,3',4',6/-hexanitrodiphenylether  according  to  the 
instructions  of  the  patent3  if  it  is  suspended  in  concentrated  sulphuric 
acid  and  the  mixture  is  poured  into  three  to  four  times  its  volume 
of  mixed  acid  (nitric  acid,  sp.  gr.  1.49  and  10%  oleum).  This 
mixture  is  heated  to  100°  and  after  some  time  the  hexanitrodiphenyl- 
ether  separates  out  as  a  solid.  If,  however,  10  g.  of  the  2,4,6,3'- 
tetranitrodiphenylether  is  suspended  in  50  cc.  of  concentrated  sul- 
phuric acid,  and  this  mixture  is  poured  into  150  cc.  of  mixed  acid, 
composed  of  25  cc.  HNO3,  sp.  gr.  1.49,  and  125  cc.  of  10%  oleum, 
and  then  heated  for  an  hour  or  two  at  90  °,  there  is  obtained  a  product 
which  on  recrystallization  from  acetic  acid  or  toluene  melts  at 
203-204°,  cor.  This  is  the  pentanitrodiphenylether  and  not  the 
hexa  compound.  This  penta  compound  is  the  2,4,6, 3 ',4 '-penta- 
nitrodiphenylether which  is  obtained  according  to  the  patent  at 
110°  from  3,4-dinitrophenylether  and  the  sulphuric-nitric  acid 
mixture.4 

Analysis:     0.1578  g.  of  the  substance  gave  23.90  cc.  N  at  18°  under  776  mm. 

Nitrogen  found:     17.78%. 

Nitrogen  calculated  for  pentanitrodiphenylether:     17.73%. 

Even  if  10  g.  of  tetranitrodiphenylether  was  dissolved  in  40  cc.  of 
nitric  acid,  sp.  gr.  1.49,  and  the  mixture  at  45°  poured  into  the 
mixed  acid,  formed  from  75  cc.  of  nitric  acid,  sp.  gr.  1.49,  and  150 

1  D.  R.  P.  281,053;  Chem.  Zentr.  Bl.,  I,  74  (1915).   As  we  have  not  been  able  to  obtain 
this  patent  because  of  political  events,  we  have  followed  Escales,  "Nitrosprengstoffe," 
81. 

2  Following  Escales,  "Nitrosprengstoffe,"  Leipzig,  1916,  82. 

3  Escales,  loc.  cit. 

4  D.  R.  P.  281,053;  Chem.  Zentr.  Bl,  1915,  I,  74. 


12        BRISANT  NITRO  EXPLOSIVES:  VAN  DUIN  AND  VAN  LENNEP 

cc.  of  10%  oleum,  and  the  whole  heated  to  90°  during  an  hour  or 
two,  we  still  obtain  the  pentanitroderivative  cited  above.  How- 
ever we  have  obtained  the  2,4,6,3/,4',6'-hexanitrodiphenylether  by 
using  more  nitric  acid  (sp.  gr.  1.49,)  and  30%  oleum.  The  solution 
of  10  g.  of  2,4,6,3'-tetranitrodiphenylether  in  40  cc.  of  nitric  acid, 
sp.  gr.  1.49,  is  brought  to  70°  in  a  mixture  of  90  cc.  of  nitric  acid, 
sp.  gr.  1.49,  and  170  cc.  of  30%  oleum,  and  the  whole  heated  during 
four  hours  to  90°.  There  is  thus  obtained  a  white  solid  which  melts 
in  a  sluggish  manner  between  240°  and  265°;  its  recrystallization 
is  attended  with  great  loss  (±50%);  it  is  best  to  use  nitric  acid, 
sp.  gr.  1.49,  at  first,  and  then  glacial  acetic  acid.  Melting  point, 
278°,  cor.  (after  200°,  10°  per  minute).  However,  the  purest 
product  begins  to  soften  about  265  °.1 

When  the  filtrate  from  the  recrystallization  in  nitric  acid,  sp.  gr. 
1.49,  is  poured  into  water,  a  precipitate  is  obtained  which  melts  in 
a  sluggish  manner  between  215°  and  250°;  this  was  at  first  believed 
to  consist  of  the  2,4,6,3',4/,6/-hexanitrodiphenylether,  contaminated 
with  2,4,6,3',4/-pentanitrodiphenylether.  But  if  this  product  is 
nitrated  as  directed  above,  that  is  to  say  with  nitric  acid  of  1.49 
sp.  gr.  and  30%  oleum  during  four  hours  at  90°,  the  melting  point 
does  not  vary  appreciably.  This  mixture  is  then  probably  composed 
of  2,4,6,3',4/,6/-and  2,4,6,2',3',4'-hexanitrodiphenylether.2  A  de- 
termination of  nitrogen  shows  that  this  mass  is  composed  almost 
entirely  of  hexanitro  derivatives.  0.1462  g.  of  the  substance  gives 
24.20  cc.  nitrogen  at  22°  under  767  mm. 

Nitrogen  found:     18.82%. 

Nitrogen  calculated  for  pentanitrodiphenylether :     17.73%. 

Nitrogen  calculated  for  hexanitrodiphenylether :     19.10%. 

We  have  not  tried  to  isolate  from  the  mixture  the  hexanitro 
derivatives,  but  hope  to  do  this  later. 

As  it  appeared  important  to  be  able  to  compare  the  stabilities, 
sensitiveness,  etc.,  of  2,4,6,3/,4/,6'-hexanitrodiphenylether  and 
2,4, 6, 2', 4 ',6 '-hexanitrodiphenylether,  we  have  attempted  to  pre- 
pare this  dipicrylic  ether  as  follows: 

At  the  outset  we  may  say  that  we  are  not  much  surprised  that  we 
did  not  obtain  the  result,  inasmuch  as  the  Griesheim  Chemical 

1  According  to  D.  R.  P.  281,053,  already  cited,  the  melting  point  is  about  269°,  not 
cor. 

2  We  do  not  include  the  formation  of  2,4, 6, 2 ',3 ',6 '-hexanitrodiphenylether  made  by 
us  in  our  tests  long  ago  for  the  preparation  of  2,4,6,2',4',6'-hexanitrodiphenylether. 


BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP        13 

Company  patented1  the  2,4,6,2 ',4'-pentanitrodiphenylether  but  not 
the  dipicrylic  ether,  although  the  latter  would  be,  as  an  explosive, 
superior  to  the  former. 

1.  Ten  g.  2,4,6,2',4'-pentanitrodiphenylether  were  dissolved  in 
40  cc.  of  nitric  acid,  sp.  gr.  1.49,  and  then  nitrated  during  four  hours 
at  90°  with  a  mixture  of  90  cc.  of  nitric  acid,  sp.  gr.  1.49,  and  170 
cc.  of  30%  oleum.     The  initial  compound  was  found  unaltered. 

2.  Two    g.    of    2,4,6,2',4'-pentanitrodiphenylether    were    boiled 
during  one-half  hour  with  a  mixture  of  40  cc.  of  real  nitric  acid  and 
20  cc.  of  20%  oleum,  after  which  the  nitric  acid  was  eliminated.2 
On  pouring  this  mixture  into  water,  no  precipitate  was  obtained, 
not  even  a  cloud.     The  penta  derivative  must  then  have  been  oxi- 
dized. 

3.  Nitration  with  real  nitric  acid  and  phosphoric  anhydride. 
On  nitrating  2,4,6,2',4'-pentanitrodiphenylether  with  30  cc.  of  real 
nitric  acid  and  21  g.  of  P2Oi  during  two  hours  at  40  °,3  the  initial 
product  remains  unchanged. 

4.  It  is  the  same  if  3  g.  of  2,4,6,2',4'-pentanitrodiphenylether  are 
treated  with  a  mixture  of  30  cc.  of  real  nitric  acid  and  30  cc.  acetic 
anhydride,  and  heated  for  some  time  at  30-40°,  or  allowed  to  re- 
main for  a  week  at  ordinary  temperatures;  not  the  least  change  is 
observed.4 

5.  If  a  solution  of  picryl  chloride  or  bromide5  is  boiled  during 
five  hours  with  silver  picrate,6  there  is  no  transformation. 

6.  The  same  result  is  obtained  when  10  g.  of  picryl  chloride  are 
heated  seven  hours  at  100°  with  2  g.  of  silver  picrate. 

7.  A  reaction  is  obtained,  however,  if  given  quantities  of  picryl 
chloride  and  silver  picrate  are  heated  in  absolute  alcohol,  but  this 
reaction   is   not    of   the    kind   desired.     We   dissolved    6.8   g.    of 
silver  picrate  in   230    cc.    of  boiling  absolute  alcohol,   and  then 
added  5  g.  of  picryl  chloride  when  the  silver  chloride  commenced 
immediately  to  separate.     The  whole  was  allowed  to  boil  during 
ten  hours,  after  which  the  reaction  was  apparently  complete.     The 

1  D.  R.  P.  81,970;  Escales,  "Nitrosprengstoffe,"  Leipzig,  1915,  67. 

2  Picryl  bromide  appears  to  have  been  prepared  from  2,4,-dinitrobromobenzene  by 
Jackson  and  Earle,  Amer.  Chem.  Journ.,  29,  212  (1903). 

3  We  do  not  nitrate  at  a  higher  temperature  because  already  at  45°  a  notable  amount 
of  N2Os  from  decomposition  is  formed. 

4  See  Franchimont  and  Friedmann,  Rec.  trav.  chim.,  28,  192  (1908). 

5  Jackson  and  Earle,  loc.  cit. 

6  Kast,  Zeitschr.  f.  d.  ges.  Schiess-  und,  Sprengstoffw.,  6,  32  (1911). 


14        BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN LENNEP 

silver  chloride  was  filtered  and  the  alcohol  distilled.  The  residue 
obtained  was  then  extracted  twice  with  water  as  rapidly  as  possible1 
in  order  to  eliminate  the  silver  picrate  which  had  not  been  trans- 
formed when  the  material  was  recrystallized  in  absolute  alcohol. 
After  several  recrystallizations  there  was  obtained  a  compound 
melting  at  79°  which  is  not  lowered  by  mixing  with  2,4,6-trinitro- 
phenetol.  The  silver  picrate  has  then  acted  to  remove  the  chlor- 
hydric  acid  produced  from  the  action  of  picryl  chloride  on  alcohol. 
We  believe  that  according  to  the  results  which  have  been  enumerated 
we  are  warranted  in  concluding  that  the  formation  of  2,4, 6,2', 4', 6'- 
is  impossible  because  of  stereochemical  reasons. 

XIV.     2,4,6,2',4',6'-Hexanitrodiphenylsulphide 

NO2  NO2 

— v  / — \ 

"> s— \     yN°2 

"NO2  NO2 

After  having  stated2  that  the  nitro  derivatives  of  diphenylsulphide 
can  be  prepared  by  the  action  of  alkaline  sulphides  on  chloronitro- 
benzene,  "Sprengstoff  A.  G.  Carbonit"3  found  it  could  obtain  a 
better  yield  of  the  2,4,2', 4'-tetranitrodiphenylsulphide  by  the  action 
of  two  molecules  of  2,4-dinitrochlorobenzene  and  two  molecules 
of  sodium  hyposulphite,  according  to  the  following  expression : 

2C6H3(NO2)2C1  +  2Na2S2O3  =  C6H3(NO2)2S  C6H3(NO2)2  +  2NaCl  +  Na2S3O6     (I) 

When,  however,  they  sought  to  obtain  the  dipicrylsulphide  from 
picryl  chloride  by  a  similar  reaction  they  obtained  a  dark  flocculent 
mass.  From  the  newer  researches  of  the  "Sprengstoff  A.  G.  Car- 
bonit,"4 the  2,4,6,2/,4/,6'-hexanitrodiphenylsulphide  can  be  obtained 
provided  but  one  molecule  instead  of  two  of  the  hyposulphite  is 
employed  and  the  sulphuric  acid  formed  in  the  reaction  is  neutralized. 
The  expression  for  this  reaction  is : 

2C6H2(NO2)3C1  +  Na2S2O3  +  H2O  =  C6H2(NO2)3.S.C6H2(NO2)3+2NaCl  +  H2SO4     (II) 

The  yield  is  about  90%.  It  is  necessary  to  employ  the  least 
excess  of  hyposulphite  in  the  reaction  as  decomposition  takes  place 
at  the  same  time  the  color  is  darkened.  The  directions  of  the 
patent  for  the  formation  of  hexanitrodiphenylsulphide  are  precise; 

1  This  is  for  the  removal  of  the  trinitrophenetol  of  hydrolysis  but  even  with  boiling 
water  sufficient  of  the  product  remains  for  identification. 

2  Willgerodt,  Beilstein  II,  1896,  803. 

3  D.  R.  P.  94,077. 

4  D.  R.  P.  275,037;  Chem.  Zentr.  Bl.,  1914,  II,  97.     Escales,  "Nitrosprengstoffe,"  79, 
197. 


BRISANT  NITRO  EXPLOSIVES:  VAN  DUIN  AND  VAN  LENNEP        15 

we  have  never  observed  decomposition  when  using  pure  picryl 
chloride  and  the  theoretical  quantity  of  hyposulphite;  the  least 
excess  of  hyposulphite,  on  the  contrary,  produces  decomposition. 
If  one  wishes  to  obtain  a  crude  product  which  is  sufficiently  purified 
by  a  single  recrystallization  from  alcohol-acetone,  it  will  be  prudent 
to  make  use  of  hyposulphite  in  a  quantity  a  little  below  the  theo- 
retical value. 

We  have  prepared  the  hexanitrodiphenylsulphide  as  follows: 
after  the  patent  of  which  we  have  spoken  a  solution  of  20  g.  of  picryl 
chloride  in  100  cc.  of  95%  alcohol  with  3.8  g.  of  MgCO3  suspended 
in  the  solution  is  boiled  in  a  flask  furnished  with  a  reflux  condenser. 
There  is  then  added,  little  by  little,  with  continual  agitation,  10  g. 
of  finely  pulverized  Na2S2O3.5H2O  (theory  10.03  g.).  New  portions 
of  the  hyposulphite  are  added  when  that  which  has  been  introduced 
has  completely  reacted.  When  the  reaction  is  finished  the  filtered 
crude  product  is  washed  with  alcohol,  then  weak  chlorhydric  acid, 
and  then  water.  The  yields  were  14.45  and  14.65  g.  of  the  hexanitro 
product,  which  corresponds  to  78.4  and  79.5%.  As  the  patent 
claims  a  yield  of  =>=90%  we  have  tried  the  reaction  with  greater 
quantities  of  picryl  chloride,  and  using  60  g.  of  this  substance  the 
yield  of  hexanitrodiphenylsulphide  fell  to  40  g.  or  72.4%.  This  is 
why  after  establishing  the  fact  that  the  quantity  of  sulphuric  acid 
corresponds  to  the  weight  of  hexanitrodiphenylsulphide  we  have 
determined  the  quantity  of  acid  in  the  filtrate  of  a  preparation 
made  from  20  g.  of  picryl  chloride.  From  reaction  II  it  is  shown 
that  3.963  g.  of  sulphuric  acid  should  be  formed;  we  have  found 
3.721  and  3.725,  which  corresponds  to  93.9%  of  the  theory.  In 
this  trial  we  have  anew  obtained  79.4%  of  hexanitrodiphenyl- 
sulphide (see  above)  which  ought  to  produce  more  sulphuric  acid 
as  indicated  by  reaction  II.  The  appearance  of  a  disagreeable  odor 
of  an  organic  sulphur  compound1  argues  also  in  favor  of  this  inter- 
pretation; however,  we  are  not  able  to  indicate  the  nature  of  this 
secondary  reaction.  The  hexanitrodiphenylsulphide  is  best  re- 
crystallized  in  alcohol-acetone  or  in  glacial  acetic  acid;  the  purest 
product  has  a  melting  point  of  233-234°,  cor.2 

XV.     2,4,6,2  ',4  ',6  '-Hexanitrodiphenylsulphone 
NO2        O.x    ^O      NO2 

NO2<          > S <(         >NO2 


NO2 

1  The  hexanitrodiphenylsulphide  has  no  odor. 

2  According  to  Beilstein  II,  803,  the  melting  point  is  226°,  not  cor. 


1 6        BRISA NT  NITRO  EXPLOSI VES:    VAN  D UIN  AND  VAN  LENNEP 

Following  D.  R.  P.  269,8621  of  the  "Sprengstoff  A.  G.  Carbonit," 
hexanitrodiphenylsulphide  can  be  transformed  into  its  corresponding 
sulphone  by  treating  it  in  suspension  in  nitric  acid,  or  in  a  mixture 
of  chromic  and  acetic  acids,  with  bichromates  or  oxidizing  com- 
pounds of  manganese.  This  compound  has  been  assigned  a  per- 
oxide formula: 

C,H,(NO,)3v       /O 

\o/    I 

/*\  \ 

C6H2(N02)3/      X0 

but  this  has  been  contested  by  Stettbacher2  on  account  of  the  great 
stability  of  the  compound.  Up  to  the  present  we  have  obtained 
no  other  hexanitro  derivative  of  oxidation,  following  the  process 
indicated,  on  using  other  oxidizers  such  as  CrO3  and  K2Cr2O7.  The 
treatment  of  the  sulphide  by  potassium  permanganate  in  suspension 
in  nitric  or  sulphuric  acid  leaves  the  material  unchanged. 

The  use  of  the  theoretical  quantity  of  chromic  acid  having  given 
us  satisfactory  results,  we  operated  in  the  following  manner:  17.1  g. 
of  hexanitrodiphenylsulphide  were  put  in  suspension  in  100  cc.  of 
nitric  acid,  sp.  gr.  1.49,  then  5  g.  of  finely  pulverized  chromic  acid 
were  added.3  The  mass  was  allowed  to  stand  at  the  ordinary  tem- 
perature, with  agitation  from  time  to  time,  until  the  disappearance 
of  the  chromic  acid,  which  took  about  15  days.  During  this  time 
the  sulphide  disappeared  also,  while  there  was  formed  a  voluminous, 
very  slightly  colored  product.  This  was  filtered,  washed  until  acid 
reaction  disappeared,  recrystallized  in  alcohol-acetone,  and  the 
sulphone  obtained.  This  was  a  yellowish  white  compound,  melting 
at  307°,  cor.  (after  250°,  10°  per  minute).4 

Analysis:     0.127  g.  of  substance  gives  18.75  cc.  nitrogen  at  16°  and  772  mm. 

Nitrogen  found:     17.40%. 

Nitrogen  calculated  for  hexanitrodiphenylsulphone:     17.22%. 

By  this  process  there  is  obtained  a  sulphone  contaminated  by  a 
little  sulphide  which  may  be  removed  by  solution  in  nitric  acid  of 
1.49  sp.  gr.  In  fact,  it  is  necessary  to  employ  as  much  as  200  cc. 
of  nitric  acid  for  10  g.  of  sulphide.  On  account  of  the  slowness  of 
the  reaction  we  have  tried  to  increase  its  activity  by  heat,  but  we 
nave  not  obtained  any  better  result  with  either  nitric  or  acetic  acid. 

1  Escales,  "Nitrosprengstoffe,"  Leipzig,  1915,  81,  283. 

2  Stettbacher,  Zeitschr.  f.  d.  ges.  Schiess-  und  Sprengstoffw.,  11,  115  (1916). 

3  It  is  strongly  recommended  that  finely    pulverized  chromic  acid    be  used  because 
the  reaction  is  very  slow. 

4  F.-om  this  melting  point,  the  explosion  temperature  of  250-255°  given  in  the  patent 
must  be  inexact. 


BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP        1 7 

We  entirely  agree  with  the  statement  of  Stettbacher1  as  concerns 
the  constitution  of  the  product.  To  the  argument  furnished  by  this 
author  as  to  resistance  to  high  temperatures,  we  wish  to  add:  1. 
No  iodine  is  separated  when  the  sulphone,  dissolved  in  glacial  acetic 
acid,  is  treated  with  potassium  iodide.  2.  Sensitiveness  to  shock: 
as  measured  by  the  drop  hammer  it  is  less  sensitive  than  the 
sulphide2;  if  the  sulphone  were  a  peroxide,  its  sensitiveness  would 
increase. 

XVI.     2,4,6-Trinitrodimethyldinitraminebenzene 
CH3  NO2 
\/ 

NO; 


NO2 

This  compound  has  been  prepared  by  Van  Romburgh  from  the 
1,3-dimethylphenylenediamine,3  the  tetramethylmetaphenylenedi- 
amine4  and  the  2,4,6-trinitro-3-methylaminophenylmethylnitranr 
ine;5  by  Blanksma6  from  the  l,3-dimethylamine-2,4-dinitrobenzene; 
and  by  Blanksma  and  Meerum  Terwogt7  from  the  4,6-dinitrodi- 
methylmetaphenylenediamine  with  concentrated  nitric  acid. 

We  made  use  of  a  process  analogous  to  that  of  Van  Romburgh,8 
with  the  difference  that  we  have  not  used  as  our  point  of  departure 
the  monomethyl  compound  but  have  employed  the  dimethylamino- 
trinitrophenylmethylnitramine  which  we  have  obtained  from  the 
tetranitrophenylmethylnitramine  by  using  less  of  the  dimethyl- 
amine  than  Schepers.9  This  last  preparation  was  made  as  follows: 
To  300  cc.  of  the  8%  aqueous  solution  of  dimethylamine  was  added, 
in  small  portions,  with  constant  cooling  by  water,  140  g.  of  tetra- 
nitrophenylmethylnitramine  and  the  mixture  allowed  to  stand  for 
half  an  hour.  It  was  then  poured  promptly  into  250  cc.  of  10% 
chlorhydric  acid  and  the  dimethylaminotrinitrophenylmethylni- 

1  Stettbacher,  loc.  cit. 

2  See  page  29,  Table  II. 

3  Van  Romburgh,  Rec.  trav.  chim.,  6,  251  (1887). 

4  Van  Romburgh,  Ibid.,  7,  3  (1888). 

5  Van  Romburgh,  Ibid.,  8,  280  (1889). 

6  Blanksma,  Ibid.,  27,  27,  49  (1907). 

i  Blanksma  with  Meerum  Terwogt,  Ibid.,  21,  291  (1901). 

8  Van  Romburgh,  Ibid.,  8,  280  (1889). 

9  Schepers,  "Dissertatie,"  Utrecht,  1913,  48;  used  for  3  gr.  of  nitramine,  5  gr.  dimethyl- 


18        BRISA NT  NITRO  EXPLOSIVES:  VAN  D UIN  AND  VAN  LENNEP 

tramine  formed  was  filtered,  washed  until  the  disappearance  of  the 
acid  reaction,  and  then  boiled  with  alcohol.  Yield,  100  g.1  The 
crude  product  was  then  introduced  in  small  portions  into  nitric  acid, 
sp.  gr.  1.49,  and  heated  to  70-80°,  in  order  to  effect  the  replace- 
ment of  the  dimethylamine  group  by  the  methylnitramino  group. 
If  sufficient  nitric  acid  is  employed  there  is  obtained  by  recrystalli- 
zation  a  very  nearly  colorless,  almost  white,  product.  This  crystal- 
lization, as  stated  by  Van  Romburgh,  is  best  effected  in  alcohol- 
acetone.  The  purified  product  melts  at  about  206°,  cor.  (after 
150°,  10°  per  minute);  it  is  to  be  remarked  that  the  technical 
preparation  corresponds  to  that  of  Van  Romburgh  who  used  al- 
kalized metaphenylenediamines.2 

XVII  and  XVIII.     Dipicrylamine  and  2,4,6,2',3',4'-Hexanitrodiphenylamine 
NO2  NO2  NO2  NO2  NO2 


>NO2  N02<T          >—  N— — ^        >NO2 

NO2  NO2  NO, 

For  the  preparation  and  properties  of  these  bodies,  consult  the 
published  memoirs.3 

xix.   Tetra-        We   have   prepared    tetranitrophenol    according   to 

nitrophenol      Blanksma4    from    w-nitrophenol    and    sulphuric-nitric 

acid.      The  use  of  real  nitric   acid    is   not    essential; 

NO:/    xiNO2    with  acid  of  sp.  gr.  1.49  the  reaction  goes  on  as  described 

by  Blanksma.     However,  it  is  well  not  to  use  at  one 

N°2        time  more  than  5  g.  of  m-nitrophenol.     By  recrystal- 

lization  from  dry  chloroform  we  have  obtained  a  melting  point  of 

140°,  cor. 

STABILITY 

Although  the  literature  of  chemistry  is  quite  extended  on  the 
subject  of  the  stability  of  nitroglycerine,  guncotton  and  smokeless 
powder,  it  is,  on  the  contrary,  very  limited  as  concerns  the  brisant 
military  nitro  explosives  and  explosives  used  for  industrial  purposes. 
For  these  last,  the  stability  constants  have  been  established  from 
preliminary  trials  by  the  Eighth  International  Congress  of  Applied 
Chemistry5  on  the  initiative  of  Will  and  Lenze.  The  German 

1  See  Van  Dum,  Rec.  trav.  Mm.,  37,  111  (1917). 

2  French  patent  391,107;  Escales,  "Nitrosprengstoffe,"  Leipzig,  1915,  282. 

3  Van  Duin  and  Roeters  Van  Lennep,  Rec.  trav.  Mm.,  38,  358  (1919). 
«  Blanksma,  Ibid.,  21,  254  (1902). 

5  Zeitschr.  j.  d.  ges.  Schiess-  und  Sprengstoffw.,  7,  435  (1912);  8,  345,  370  (1913). 


BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP       1 9 

Railway  Commission  has  adopted  these  constants  for  nitro  ex- 
plosives.1 The  reason  for  much  of  the  delay  in  the  examination 
of  nitro  explosives  is  due  to  the  peculiar  characteristics  of  the  nitro 
compounds,  picric  acid  and  trinitrotoluene.  Verola2  has  shown 
that  trinitrotoluene  may  be  maintained  during  100  hours  at  100° 
without  its  showing  any  alteration;  the  setting  point,  80.7°,  does  not 
change.  We  have  no  similar  data  for  picric  acid  at  our  disposal; 
we  notice  only  that  in  Holland  picric  acid  (and  the  same  may  be 
said  of  trinitrotoluene)  must  respond  to  such  a  trial  as  the  following : 
10  g.  heated  at  95°  during  three  hours  did  not  give  off  the  least 
trace  of  nitrogen  oxides.  Picric  acid  endures  this  test  very  well; 
it  may  even  be  repeated  during  several  weeks  by  heating  it  each 
day  during  eight  hours  to  95°,  without  the  least  nitrous  vapor 
making  its  appearance. 

But  the  question  of  the  stability  of  brisant  nitro  explosives  en- 
tered on  a  new  phase  with  the  employment  of  nitro  compounds  con- 
taining one  or  more  methylriitramino  or  mobile  nitro  groups.  Of 
the  first  group,  that  of  the  nitramines,  it  is  not  necessary  to  again 
take  count.  The  trinitrophenylmethylnitramine,  used  nearly  ex- 
clusively at  the  present  time,  is  very  stable  when  in  a  sufficiently 
pure  condition.  It  is  quite  otherwise  with  tetranitrophenylmethyl- 
nitramine  and  tetranitroaniline,  which  have  been  described  as  very 
stable,3  they  being,  however,  rapidly  decomposed  even  if  they  are 
very  pure.4  This  is  the  more  remarkable  if  we  recall  that  tetra- 
nitroaniline is  more  stable  at  70°  than  nitroglycerine,  while  at  the 
ordinary  temperature  the  contrary  is  true.  The  Nobel  Dynamite 
Factory  at  Avigliana  preserves  today  200  g.  of  the  nitroglycerine 
which  was  prepared  for  the  first  time  in  1848  by  Sobrero;  the  ni- 
trogen content  of  this  specimen  has  not  varied  up  to  the  present, 
nor  has  it  shown  the  least  trace  of  acid.5  Tetranitroaniline,  on  the 
contrary,  resists  well  tests  of  stability  at  71  °6  while  in  different 

1  Escales,  "Ammonsalpetersprengstoffe,"  Leipzig,  1909,  120. 

2  Verola,  Zeitschr.  f.  d.  ges.  Schiess-  und  Sprengstoffw.,  7,211  (1912);  Escales,  "Nitro- 
sprengstoffe,"  Leipzig,  1915,  297. 

3  Fliirscheim,  Zeitschr.  f.  d.  ges.  Schiess-  und  Sprengstoffw.,  8,  185  (1913). 

4  The  communication  of  Claessen  in  Holland  patent  no.   5,240,   stating  that  the 
2,3,5,6-tetranitro-anisol  is  notably  more  stable  than  the  trinitrophenylmethylnitramine, 
ought  to  be  regarded  as  inexact.     This  conclusion  was  based  solely  on  the  high  tem- 
perature of  inflammation,  300°. 

5  Escales,  "Nitroglycerine  and  dynamite,"  Leipzig,  1908,  3. 

6  Kast,  "Spreng-  und  Ziindmittel,"  1909,  952. 


20        BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP 

countries  a  well  determined  decomposition  has  been  observed  at 
ordinary  temperatures  after  9  weeks. 

In  our  researches  on  the  stability  of  brisant  nitro  explosives,  we 
have  not  determined  whether  these  explosives  respond  to  the  tests 
of  stability  employed  for  safety  explosives.  These  tests  are  of 
value  for  technical  products,  but  the  Abel  test,  in  which  is  observed 
the  first  disengagement  of  nitrous  vapors,  is  too  sensitive  for  these 
technical  products.1  This  test  is  made  in  duplicate:  10  g.  of  the 
explosive  are  heated  in  flasks  of  determined  dimensions  during  48 
hours  at  75°,  after  which  there  should  not  be  produced  the  least 
sign  of  decomposition  as  shown  by  the  appearance  or  odor.2  For 
nitro  compounds,  it  is  further  stipulated  if  changes  are  produced 
the  sensitiveness  to  shock  should  be  determined  on  a  sample  in 
which  the  change  is  most  marked.3  As  we  have  tried  chemically 
pure  compounds  only,  we  have  observed,  following  Abel,  whether 
or  not  a  change  was  produced  by  them  in  starch-zinc-iodide  papers 
moistened  with  glycerine  solution.  The  eventual  presence  of 
nitrogen  oxides  thus  shown  can  be  due  only  to  the  decomposition 
of  the  explosive  because  of  the  purity  of  the  same,  and  this  gives 
a  good  idea  of  the  stability.  In  our  stability  trials  we  have  first 
sought  to  ascertain  if  the  explosive  responds  to  the  test  applied  in 
Holland  to  picric  acid  and  to  trinitrotoluene,  that  is  to  say,  if  on 
heating  10  g.  to  95°  during  3  hours  the  least  decomposition  is  to  be 
observed.  If  the  result  of  this  test  was  good,  the  substance  was 
then  heated  during  30  days  at  the  rate  of  8  hours  per  day.  If  after 
this  period  the  material  showed  no  change,  the  test  was  stopped 
since  its  prolongation  seemed  to  be  without  significance.  The 
term  of  30  days  was  fixed  upon  arbitrarily.  If  the  explosive  failed 
to  pass  that  test,  a  determination  of  its  stability  was  made  at  lower 
temperatures. 

In  the  tests  of  stability  at  32°,  50°,  95°,  10  g.  of  the  substance 
were  heated  in  flasks  of  the  kind  specially  used  for  determining  the 
stability  of  smokeless  powder  and  guncotton.  These  flasks  have 
a  capacity  of  29.3  cc.  (=*=3  cc.)  and  a  height  measured  just  to  the 
stopper  of  46.1  mm.  (±2);  they  ought  to  pass  the  test  called  the 
"ether  test,"  which  consists  in  placing  10  cc.  of  ether  in  a  flask  and 
weighing  the  whole;  after  24  hours  of  rest  at  the  ordinary  tem- 

1  Lenze,  Zeitschr.  f.  d.  ges.  Schiess-  und  Sprengstoffw.,  4,  303  (1909). 

2  Zeitschr.  f.  d.  ges.  Schiess-  und  Sprengstoffw.,  8,  370  (1913). 

3  Escales,  "Ammonsalpetersprengstoffe,"  120. 


BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP      2 1 

perature  the  diminution  in  weight  ought  not  to  surpass  100  mg. 
For  the  trials  at  other  temperatures  we  have  employed  tubes  16 
cm.  in  length  and  17  mm.  in  diameter,  with  a  2  cm.,  well  ground, 
glass  stopper;  these  tubes  passed  the  ether  test;  they  were  placed 
in  water  baths  at  constant  temperature,  which  is  not  possible  with 
flasks.  The  zinc-iodide-starch  paper  was  prepared  as  follows: 
100  cc.  of  water  containing  4  g.  of  starch  and  20  g.  of  zinc  chloride 
were  boiled  during  2  hours.  2  g.  of  zinc  iodide  and  a  liter  of  water 
were  then  added  and  the  whole  filtered.  In  this  solution  strips 
of  Schleicher  and  Schull's  No.  590  filter  paper  were  soaked  during 
one  minute  and  then  dried  in  darkness  and  preserved  in  hermeti- 
cally closed  boxes.  For  use  the  paper  thus  prepared  is  moistened 
with  a  10%  solution  of  glycerine  by  placing  a  drop  on  the  lower 
part.  We  have  described  the  preparation  of  this  zinc-iodide- 
starch  paper  because  there  is  attributed  to  it  a  certain  importance1 
and  this  is  an  essential  thing  for  the  comparison  of  these  tests. 
We  give  below  results  obtained  with  the  different  explosives  and 
data  of  the  literature,  the  compounds,  prepared  according  to  the 
methods  described  in  the  preceding  pages,  being  in  a  state  of  great 
purity.2 

1 .  The  following  compounds  have  responded  to  the  tests  described 
in  the  preceding  pages,  which  consist  in  heating  10  g.  of  the  ma- 
terial to  95°  without  the  least  trace  of  nitrous  acid  having  been 
disclosed.  These  are:  Trinitrophenylmethylnitramine,  trinitro- 
amidophenol,  -anisol  and  -phenetol,  trinitrometaphenylenediamine, 
trinitromethylnitraminophenol,  aminotrinitrophenylmethylnitram- 
ine,  hexanitrodiphenyl  sulphide  and  sulphone,  and  dipicrylamine. 
For  each  of  these  substances  the  test  has  been  continued  during 
30  days  at  a  rate  of  8  hours  per  day  without  the  least  change.  On 
account  of  the  gr£at  importance  of  the  trinitrophenylmethylnitram- 
ine  to  our  modern  explosives  industry,3  we  have  continued  the  test 
for  this  last  during  185  days,  without  having  observed  the  least 
decomposition.  In  the  case  of  the  trmitrodimethyldinitramino- 
benzene,  one  flask  has  shown  a  reaction  after  three  days,  while 
after  four  days  four  flasks  have  shown  a  decomposition. 

2a.   Tetranitroaniline.     According  to  Fliirscheim,4  it  is  easy  to 

1  See  Zeitschriftf.  d.  ges.  Schiess-  und  Sprengstoffw.,  9,  293  (1914);  there  is  given,  with 
details,  the  preparation  of  the  paper  employed  in  England. 

2  For  more  details,  see  Van  Duin,  "Dissertatie,"  Utrecht,  1918,  76-84. 

3  See  Van  Duin  and  Brackmann,  Client.  Weekbl.,  16,  501  (1919). 

4  Flurscheim,  Zeitschr.  f.  d.  ges.  Schiess-  und  Sprengstoffw.,  8,  185  (1913). 


22        BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP 

prepare  a  product  which  will  not  cause  coloration  of  the  reagent 
paper  after  60  minutes,  exposure  at  71°;  the  same  author  indicates 
that  the  stability  at  120°  equals  that  of  tetryl.  However,  Stett- 
bacher1  has  already  shown  that  the  purest  tetranitroaniline  de- 
composes after  8  days,  this  being  attributed  to  the  reaction  between 
the  orthonitro  and  the  amino  groups.2 

Test  at  70°.  After  two  hours'  heating,  no  trace  of  nitrogen  oxide 
was  observed;  this  is  also  the  case  after  three  hours. 

Test  at  60°.  No  decomposition  after  18  hours,  nor  even  after 
26  hours. 

At  50°.  We  have  heated  the  specimens  day  and  night;  the  sev- 
enteenth day  two  out  of  four  flasks  gave  a  positive  reaction. 

At  32°.  The  reagent  paper  has  shown  the  presence  of  nitrogen 
oxide  compounds  after  9  weeks. 

2b.  Acetyltetranitroaniline.  Special  stability  tests  have  not 
been  made  on  this.  We  mention  it  only  because  the  product, 
purified  as  described  above,  shows  an  acid  decomposition  after  two 
months  of  preservation  in  a  well  stoppered  flask. 

2c.  Tetranitrophenylmethylnitramine.  Stettbacher3  has  pre- 
sented the  hypothesis  that  this  compound  would  be  more  stable 
than  tetranitroaniline.  As  will  be  shown,  precisely  the  contrary  is 
true. 

Stability  at  60°.  Of  four  flasks  tested,  two  have  given  after  one 
hour  a  feeble  reaction  with  the  zinc-iodide-starch  paper;  after  four 
hours  the  four  flasks  have  each  given  a  strong  reaction. 

Stability  at  50°.  After  15  days  the  four  samples  have  given  a 
decided  reaction. 

Stability  at  32°.  Two  flasks  have  given  a  positive  reaction  after 
four  weeks  and  the  others  after  five  weeks. 

We  insist  that  it  is  not  advisable  to  introduce  the  reagent  paper 
into  the  tubes  used  for  the  stability  test  of  tetranitro  compounds, 
which  easily  react  when  warmed  with  water  vapor.  This  is  why 
we  have  made  our  tests  in  this  search  of  the  nitrogen  oxide  com- 
pounds by  introducing  zinc-iodide-starch  paper  into  the  test  tubes 
from  time  to  time  and  keeping  them  there  for  but  about  30  seconds. 
The  same  error  attends  the  use  of  other  reagents  which  have  been 

1  Stettbacher,  Zeitschr  f.  d.  ges.  Schiess-  und  Sprengstoffw.,    11,  114  (1916). 
1  Stettbacher,  loc.  cit.;  Escales  and  Stettbacher,  "Initialexplosivstoffe,"  Leipzig,  1917, 
250,  2,54. 

3  Stettbacher,  Zeitschr.  f.  d.  ges.  Schiess-  und  Sprengstoffw.,  11,  114  (1916). 


BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP       23 

proposed  for  testing  the  stability  of  compounds  easily  yielding 
nitrogen  oxide  derivatives  in  the  presence  of  water  vapor.1 

2d.  TetranitrophenoL  We  have  not  determined  the  stability 
of  this  compound  except  at  70°,  on  account  of  the  difficulty  in  ob- 
taining the  well  purified  product.  The  results  obtained  are  other- 
wise sufficient  for  all  our  purposes.  The  tetranitrophenol  appears 
to  behave  like  other  tetranitro  compounds.  The  presence  of 
nitrogen  oxides  was  not  shown,  however,  after  maintaining  the 
tetranitrophenol  at  70°  during  three  hours,  but  after  four  hours  the 
reaction  was  positive. 

2e.  2,4,6,3' ,4' ,6'-Hexanitrodiphenyleiher.  In  spite  of  the  pres- 
ence of  the  mobile  nitro  group,  no  decomposition  had  taken  place 
after  heating  for  three  hours  at  95  ° ;  after  eight  hours  the  reaction 
was  positive. 

2f.  2,4,6,2' ,3' ,4'-Hexanitrodiphenylamine.  As  this  product  is 
difficult  to  obtain,  we  have  simply  observed  whether  its  stability  is 
markedly  diminished  by  the  replacement  of  an  immobile  nitro 
group  in  the  dipicrylamine  by  a  mobile  group.  It  is  in  effect  thus: 
A  strong  reaction  with  the  zinc-iodide-starch  paper  was  observed 
after  heating  one  hour  at  95°. 

3.  Trinitromeihylnitramino-anisol  and  -phenetol.  The  stability 
of  this  compound  is  markedly  less  than  that  of  the  corresponding 
phenols;  we  have  definitely  proved  our  several  preparations.  The 
anisol  after  heating  for  one  hour  at  90°  gave  no  reaction,  but  after 
two  hours  the  reaction  was  positive.  At  80°  the  test  is  negative 
during  24  hours,  positive  after  26  hours.  On  heating  the  flasks  to 
70°  at  the  rate  of  eight  hours  per  day,  a  positive  reaction  was  ob- 
served after  15  days.  At  50°  at  constant  heat,  20  weeks  were 
needed  to  render  the  reaction  positive.  With  phenetol,  there  was 
no  reaction  after  one  hour's  heating  at  90°,  but  a  marked  reaction 
after  two  hours.  The  reaction  is  much  more  manifest  than  that  of 
anisol.  At  30°,  a  reaction  after  12  hours  (none  after  10);  at  70°, 
reaction  after  7  hours'  heating,  at  the  rate  of  8  hours  per  day;  and 
at  50°,  after  20  weeks.  It  should  be  noted  that  we  have  observed 
a  less  stability  for  the  phenetol  among  our  preparations. 

We  ought  also  to  observe  that  the  nitrogen  oxides  produced  in 
our  tests  of  stability  of  tetranitro  compounds  come  from  the 

1  See  Guttmann,  Zeitschr.  f.  angew.  Chem.,  1897,  265;  Egerton,  Zeitschr.  f.  d.  ges. 
Schiess-  und  Sprengstorfiv.,  8,  390  (1913).  These  authors  have  worked  with  solutions 
of  diphenylamines,  especially  naphthylamine  and  dimethylaniline,  which  also  contain 
water. 


24        BRISANT  NITRO  EXPLOSIVES:  VAN  DUIN  AND  VAN  LENNEP 

compounds  themselves,  and  not  from  the  reaction  between  the  nitro 
product  and  the  moisture  of  the  paper.  This  is  clearly  shown  by 
the  test  made  with  three  tubes  each  containing  10  g.  of  tetranitro- 
aniline  heated  in  a  water  bath  at  70°.  The  first  tube  was  tested 
after  one  hour  and  it  gave  no  positive  reaction ;  after  two  hours  the 
second  tube  was  also  examined;  neither  of  the  two  tubes  gave  a 
positive  reaction,  but  after  three  hours  all  three  tubes  gave  a  posi- 
tive reaction.  It  is  incontestable  that  if  the  reagent  paper  had 
left  a  little  moisture  in  the  first  tube,  its  positive  reaction  should 
have  been  produced  before  the  second  and  third  trials.  Further- 
more, the  presence  of  nitrogen  oxide  compounds  can  be  disclosed 
for  a  very  pure  specimen  of  tetranitrophenylmethylnitramine,  pre- 
served in  a  sulphuric  acid  desiccator  at  a  temperature  of  32°. 

CONCLUSIONS 

a.  It  has  been  shown  that  if  the  chemically  pure  tetranitro  com- 
pounds 2,3,4,6-  decompose  more  rapidly  at  an  elevated  than  at 
ordinary  temperature,  this  may  be  attributed  to  the  separation  of 
nitrous  acid  from  nitro  group  3.     If  tetranitroaniline  be  compared 
with  tetranitrophenylmethylmtramine,   it  is   seen  that   the  most 
active  nitro  groups  have  also  the  least  stability.     The  conception 
of  Stettbacher  already  mentioned,  according  to  which  the  nitrous 
acid  disengaged  in  the  decomposition  of  tetranitroaniline  proceeds 
from  a  reaction  between  the  amido  and  the  ortho  nitro  groups,  is 
inexact,  for  the  trinitrometaphenylenediamine  and  the  aminotri- 
nitrophenylmethylnitramine,  which  ought  easily  to  undergo  this 
species  of  decomposition,  are  very  stable  compounds. 

Furthermore,  the  fact  that  dipicrylamine  is  very  stable  and  that 
2,4,6,2',3',4'-hexanitrodiphenylamine  is  not  so,  proves  that  the 
mobile  nitro  group  is  the  cause  of  the  instability  in  nitro  compounds 
possessing  such  a  mobile  group.  The  great  importance  of  the 
relative  mobility  of  this  nitro  group  is  shown  by  the  test  of  2,4,6,- 
3/,4',6'-hexanitrodiphenylether,  which  houses  the  nitro  group  in  3, 
and  is  much  less  mobile  than  the  2,4,6,2',3/,4'-hexanitrodiphenyl- 
amine. 

b.  Tests  of  trinitrophenylmethymitramme  and  trinitrodimethyl- 
dinitraminobenzene  show  that  the  influence  on  the  stability  of  the 
methylnitramino  group,  which  is  much  less  than  that  of  a  mobile 
nitro  group,  is  also  unfavorable.     When  the  products  are  sufficiently 
pure,  the  introduction  of  these  two  methylnitramino  groups  pre- 


BRISANT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP       25 

sents  no  difficulty.  In  consideration  of  the  tests  made  on  the  tetryl 
it  will  be  advisable  in  this  preparation  not  to  make  use  of  too  little 
nitric  acid. 

c.  We  cannot  explain  completely  the  trinitromethylnitramino- 
anisol  and-phenetol  from  the  point  of  view  of  absolute,  as  com- 
pared with  relative,  stability.  We  believe  also  that  a  generaliza- 
tion based  on  the  instability  of  these  compounds  to  light  "is  not 
possible ;  the  very  stable  trinitromethylnitraminophenol  is  the  more 
sensitive  to  light.  It  is  possible  in  these  compounds  that  the 
methylnitramino  group  becomes  very  mobile.  However,  it  is  not 
possible  to  establish  this  for  the  basic  agents  employed  to  produce 
the  substitution  of  the  oxyalkyl  group. 

One  can  obtain  a  fair  idea  of  the  value  of  the  mobility  of  the 
nitro  group  by  a  determination  of  the  heat  of  combustion.  This 
determination  should  be  made,  on  the  one  hand,  for: 

2,4-Dinitrophenylmethylnitramine. 
2,4,6-Trinitrophenylmethylnitramine. 

2,3,4,6  -Tetranitropheny  Imethy  Initr  amine . 
and  on  the  other  hand  for : 
2,4-Dinitroaniline. 

,   2,4,6-Trinitroaniline. 

2,3,4, 6-Tetranitroaniline . 

It  would  suffice  to  give  greater  mobility  to  the  fourth  nitro  group, 
instead  of  to  the  nitramine  in  the  3  position,  to  augment  the  value 
of  the  heat  of  combustion  which  will  be  greater  for  the  passage  of 
the  trinitramine  to  the  tetranitronitramine  than  for  the  passage  of 
the  trinitroaniline  to  the  tetranitroaniline.  The  series  consisting 
of  di-,  tri-  and  tetranitrophenol  is  also  interesting  from  this  point 
of  view;  if  we  note  that  0.2  g.  of  tetranitrophenol  detonates  in  the 
determination  of  its  initial  explosion  temperature  it  is  evident  that 
the  determination  of  its  heat  of  combustion  and  probably  also  of 
the  tetranitrophenylmethylnitramine  cannot  be  effected  in  the 
explosion  calorimeter. 

DETERMINATION  OF  THE  INITIAL  EXPLOSION 
TEMPERATURE 

This  constant  of  explosives  is  the  temperature  to  which,  through 
a  well  determined  elevation  of  temperature  (see  below)  it  is  brought 
to  explode  or  inflame.  As  a  means,  of  ascertaining  the  degree  of 
purity  of  crystallizable  compounds,  this  constant  is  not  of  great 


26        BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LE NNEP 

value;  for  this  purpose  the  fusion  and  decomposition  points  are 
already  indexes;  if  then  determinations  are  made  of  the  initial  ex^ 
plosion  temperature,  it  is  to  obtain  an  indication  of  the  same  value ; 
for  while  the  decomposition  and  explosion  temperatures  are  not  the 
same  thing,  it  is  not  infrequently  the  case  with  the  brisant  nitro 
explosives  to  have  the  same  figure  for  the  two.  Only  the  circum- 
stances which  determine  the  initial  explosion  temperature  render 
it  necessary  to  use  a  larger  quantity  of  the  substance  (up  to  0.5  g.) 
to  give  this  constant  some  value,  because  one  can  better  observe 
the  decomposition  phenomena  at  high  temperature. 

Though  it  has  not  been  possible  to  determine  if  the  influence  of 
stabilization  is  as  great  for  brisant  nitro  explosives  as  for  guncotton, l 
it  appears  to  us  that  it  is  still  effective.  Guncotton  as  ordinarily  sta- 
bilized has  an  initial  explosion  temperature  of  180°,  but  this  may  fall 
to  120°,  and  even  lower  if  the  guncotton  is  insufficiently  stabilized. - 
Trinitromethylnitraminophenol,  when  pure,  has  an  initial  explosion 
temperature  of  188°;  Van  Romburgh3  has,  however,  produced  an 
explosion  at  120°  by  heating  the  impure  compound  in  an  oil  bath. 
But  the  published  information  on  decomposition  at  high  tem- 
perature4 fails  to  show  the  part  played  by  the  decomposition  prod- 
ucts which  are  formed.5 

As  has  already  been  said,  it  is  indispensable  in  the  determination 
of  the  initial  explosion  temperature  to  hold  to  precise  experimental 
conditions  in  order  to  obtain  comparable  results.  We  have  made 
our  determinations  according  to  generally  accepted  methods.6  In 
method  A,  the  substance  is  heated  above  100°  at  the  rate  of  20° 
per  minute,  and  in  method  B  (employed  in  Holland  for  smokeless 
powder  and  guncotton)  the  elevation  of  temperature  above  100°  is 
at  the  rate  of  5°  per  minute.7  The  temperatures  found  by  method 
B  are  evidently  lower  than  those  of  method  A.  We,  however,  give 
the  preference  to  heating  at  the  rate  of  5°  per  minute,  because  thus 
we  can  better  take  account  of  the  manner  in  which  the  materials 
behave  at  high  temperatures.  Certain  substances  which  give  a 

1  Precise  trials  have  not  again  been  made  on  this  subject. 

2  Brunswig,  "Explosivstoffe,"  1909,  28. 

3  Van  Romburgh,  Versl.  Kon.  Akad.  Van  Wetensch.  Amsterdam,  23,  1314  (1915). 

4  See  Hoitsema,  Zeitschr.f.  physik.  Ghent.,  21,  137  (1896). 

5  Brunswig,  "Explosivstoffe,"  29,  154  (1909);  the  information  for  guncotton  will  be 
found  in  the  bibliography. 

6  Marshall,  "Explosives,"  etc.,  1915,  588;  Escales,  VI,  427. 

7  See  also  Brunswig,  "Explosivstoffe,"  1909,  28. 


BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP       27 


more  or  less  precise  initial  explosion  temperature  when  heated  at 
the  rate  of  20  °  per  minute,  do  not  give  the  same  phenomenon  when 
heated  at  the  rate  of  5°  per  minute  because  the  decomposition  is 
more  progressive.  In  method  A  we  have  used  0.2  g.  (the  quantity 
can  vary  from  0.2  to  0.5  g.)  and  in  method  B  we  have  used  the  pre- 
scribed weights,  that  is  to  say,  0.1. 

TABLE  I 
Table  of  initial  explosion  temperatures1 


NAME  OP   EXPLOSIVE 

TEMPERA- 
TURE OF 
EXPLOSION 
METHOD  A 

TEMPERA- 
TURE  OP 
EXPLOSION 
METHOD  B 

REMARKS 

Trinitrotoluol  

Degrees 
321 

Decrees 
304 

Picric  acid  

316 

309 

Trinitrophenylmethylnitramine  

196 

187 

3   out   of   12   with    pro- 

Tetranitroaniline   

247 

237 

gressive  decompn.  (B) 
2  out  of  6.  id. 

Trinitroamidophenol  

250 

231 

4  out  of  6.  id. 

Trinitroamidoanisol  

254 

238 

Trinitroamidophenetol  

257 

236 

4  out  of  6.  id. 

Trinitrometaphenylenediarnine  

335 

320 

Tetranitrophenylmethylnitramine  .... 
Trinitromethylnitraminophenol  

175 
197 

162 
188 

Trinitromethylnitraminoanisol  

198 

187 

1  out  of  6.  id. 

Trinitromethylnitraminophenetol.  .  .  . 
Aminotrinitrophenylmethylnitramine. 
2,4,6,3  ',4  ',6  '-Hexanitrodiphenylether  . 
Hexanitrodiphenylsulphide  

202 
201 

318 
319 

192 
190 
313 
302 

4  out  of  6.  id. 
1  out  of  6.  id. 

Hexanitrodiphenylsulphone  

308 

297 

Trinitrodimethyldinitraminobenzene  . 
Dipicrylamine  

214 
258 

197 
250 

3  out  of  6  not  observed; 

2,4,6,2  ',3  ',4  '-Hexanitrodiphenylamine 
Tetranitrophenol  

287 
251 

282 
245 

the    substance    is    pro- 
gressively   decomposed. 

(B) 

According  to  A,  detona- 

tion. 

1  For  more  detailed  information,  see  Van  Duin,  "Dissertatie,"  Utrecht,  1918,  89-98. 

The  compounds  have  been  purified  as  for  the  tests  for  stability; 
in  addition,  they  were  pulverized  in  advance.  We  have  used  those 
which  passed  a  sieve  of  361  openings  per  sq.  cm.  with  a  diameter 
of  wire  of  0.195  mm.  and  which  have  remained  on  a  sieve  of  529 
openings  with  a  diameter  of  wire  of  155  mm.  In  this  way  our  com- 
pounds have  been  pulverized  to  a  uniform  fineness,  which  offers  an 
advantage  in  that  they  occupy  very  nearly  the  same  space  in  the 


28        BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP 

reaction  tubes.  As  regards  the  apparatus,  we  have  used  for  method 
A  apparatus  of  the  prescribed  dimensions  and  filled  with  "Woods" 
metal  only,  but  instead  of  three  we  have  heated  but  two  tubes  at  a 
time.  For  method  B,  we  have  made  use  of  the  Hollandaise  ap- 
paratus which  is  a  little  larger  and  filled  with  oil.  We  doubt,  how- 
ever, the  importance  of  these  dimensions.  We  remark  again  that 
the  metallic  bath  was  not  agitated,  while  the  oil  bath  was,  and  this 
explains  the  more  concordant  results  obtained  under  the  latter 
conditions. 

Below  will  be  found  the  values  obtained,  presented  in  tabular 
form.  The  temperatures  given  are  corrected,  and  are  the  mean  of 
six  determinations  or  less. 

CONCLUSIONS 

a.  In  the  determination  of  initial  explosion  temperatures  it  is 
recommended  that  both  methods  A  and  B  be  used,  even  though  one 
apprehends  that  the  behavior  of  the  explosives  at  high  temperature 
is  different  for  each  case.     It  is  thus,  for  example,  that  one  per- 
ceives that  tetryl  decomposes  when  heated  at  the  rate  of  5°  per 
minute,  while  nothing  is  observed  when  the  temperature  rises  at  the 
rate  of  20°  per  minute.     Tetranitrophenol,  treated  by  method  B, 
is  inflamed,  and  ordinarily  the  phenomenon  is  vivid,  while  method 
A  produces  generally  a  detonation.     With  the  tetranitrophenyl- 
methylnitramine,  it  never  results  in  detonation  but  a  good  explosion 
with  much  flame;  we  suppose,  however,  that  this  compound  in  a 
sufficiently  great  quantity,  will  undergo  detonation, 

b.  It  is  not  possible  to  combine  the  stability  and  the  initial  ex- 
plosion temperature  by  saying  that  of  two  explosives  that  having 
the  highest  initial  explosion  temperature  has  the  greatest  stability. 1 
For  proof  of  this,  one  should  compare  the  relative  figures  given  for 
the  stability  and  those  for  the  initial  explosion  temperature. 

c.  For  explosives  which  decompose  on  fusion,  the  temperatures 
of  decomposition  and  initial  explosion  are  generally  nearly  the  same.2 
If  the  product  does  not  decompose  on  fusion  it  is  not  possible  to  say 
a  priori  what  the  initial  explosion  temperature  is.     Thus  we  have 
it   that  tetranitrophenylmethylnitramine   fuses   at   147°;   and  the 

1  See  Claessen,  Application  for  patent  (Holland)  No.  5,240,  Aug.  17,  1915. 

2  It  follows  that  the  figures  given  for  hexanitrodiphenylsulphone,  viz.,  melting  point 
306°  cor.,  initial   explosion   temperature   250-255°,  are   erroneous    (Escales,  VI,  81). 
This  is  probably  the  initial  explosion  temperature  of  the  mixture  of  2,4,6,3 ',4 ',6'-  and 
2,4,6,2',3',4'-hexanitrodiphenylether  which  is  formed  in  the  preparation. 


BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP       29 

tetranitrophenol  at  140°;  the  initial  explosion  temperature  of  the 
latter  is  250°  and  that  of  the  former  175°,  yet  these  two  compounds 
are  excellent  examples  of  tetranitro  derivatives. 

SENSITIVENESS  TO  MECHANICAL  EFFECTS 

Of  the  four  methods  which  have  been  employed  in  the  test  of  an 
explosive  by  shock,1  notably  the  test  by  the  impact  machine,  the 
test  by  fulminate  detonators,2  the  test  of  firing  and  the  test  of  friction 
in  an  unglazed  porcelain  mortar,3  the  first  two  are  the  more  impor- 
tant because  they  enable  one  to  class  the  explosives  more  rigorously. 
Of  these  two  methods,  that  of  the  impact  machine  is  the  more 
precise.  This  is  why  we  have  applied  it  to  the  examination  of  nitro 
compounds.  Will,4  Lenze,5  Mettegang,6  Bichel,7  Kast,8  Zschokke,9 
have  made  researches  having  for  their  object  the  construction  of 
apparatus  with  which  to  obtain  certain  and  precise  results  and  also 
to  determine  the  conditions  to  which  very  close  attention  should 
be  given  during  the  execution  of  the  tests.  This  information  on 
these  matters  will  be  found  in  the  works  of  Lenze  cited  above,  and 
in  those  of  Kast,  which  give  particular  instructions. 

Concerning  apparatus  and  the  conforming  to  the  "surface  con- 
stant of  the  explosive,"  we  refer  to  Kast,  "Anleitung,"  etc.,  1908, 
1015,  and  Escales,  "Nitrosprengstoffe,"  422.  The  surface  of  the 
stamps  is,  according  to  these  authors,  I1/ 2  sq.  cm.,  but  this  value 
is  not  international.  Thus  the  dimension  of  the  apparatus  of  "The 
American  Bureau  of  Mines"  is  0.785  sq.  cm.10  of  surface,  while  that 
proposed  at  the  Eighth  International  Congress  of  Applied  Chem- 
istry is  1.27  sq.  cm.11  It  was  proposed  further  to  make  ten  tests  of 
impact,  taking  picric  acid  as  the  standard  for  comparison,  all  of 
these  measurements  to  be  made  in  the  same  apparatus  with  the 
weight  of  the  finely  pulverized  substance  varying  from  0.05  to 
0.01  g.12 

1  Will,  Zeitschr.  f.  d.  ges.  Schiess-  und  Sprengstoffw.,  1,  209  (1906). 

2  Bichel,  "Gluckauf,"  41,  1194  (1905). 

3  See  Kast,  "Spreng-  und  Ziindstoffe,"  Braunschweig,  1909,  1017. 

4  Will,  loc.  cit. 

5  Lenze,  Zeitschr.  f.  d.  ges.  Schiess-  und  Sprengstoffw.,  1,  287  (1906). 

6  Mettegang,  Ibid.,  I,  293  (1906). 

7  Bichel,  Ibid.,  3,  403  (1908).     Marinerundschau,  16,  1345  (1905). 

8  Kast,  Zeitschr.  f.  d.  ges.  Schiess-und  Sprengstoffw.,  4,  263  (1909). 

9  Zschokke,  "Militarische  Sprengtechnik,"  1911. 

10Marshall,"Explosives,  Their  Manufacture,  Properties,  Test  and  History,"  1915,  345 

11  Zeitschr.  f.  d.  ges.  Schiess-  und  Sprengstoffw.,  8,  370  (1913). 

12  According  to  Kast,  there  is  invariably  employed  at  the  "Militarversuchsamt"  of 
Berlin,  0.04  g.  of  the  substance  with  a  stamp  surface  of  0.5  sq.  cm. 


30        BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP 

It  is  also  to  be  noted  that  Wohler  and  Matter1  have  constructed  a 
form  of  impact  machine  (Fallpendel)  for  testing  initiating  explosives 
which  is  made  in  such  a  manner  as  to  permit  the  compounds  re- 
sulting from  the  explosion  to  escape  after  detonation;  this  is  neces- 
sary, for  otherwise  the  stamps  are  frequently  broken. 

On  the  subject  of  the  sensibility  of  explosives  in  general,  van't 
Hoff2  has  already  pointed  out  that  definite  atomic  combinations 
show  always  a  special  sensitiveness.  Further,  the  quantity  of 
energy  set  free  during  the  explosion  also  plays  a  part.  For  com- 
pounds of  analogous  constitution,  the  sensitiveness  appears  to  be 
a  measure  of  the  augmentation  of  the  energy  set  free,  while  strongly 
endothermic  compounds,  such  as  mercury  fulminate,  lead  azide, 
etc.,  are  as  a  rule  very  sensitive.  However,  there  intervene  also 
unknown  factors  which  one  may  expect  to  find  among  the  explosives 
which  are  the  more  sensitive  of  the  exothermic  compounds,  such 
as  lead  picrate.3  Will4  has  made  the  most  interesting  research  on 
this  subject  on  the  three  isomeric  trinitrotoluenes.  He  has  shown 
that  the  2,3,4-  isomer  is  the  most  sensitive ;  this  is  because  it  possesses 
the  most  mobile  nitro  group  in  the  3  position,  and  consequently 
possesses  the  greatest  energy.5  Then  follows  the  3,4,6-  isomer  and 
finally  the  symmetric  trinitrotoluene  which  has  no  mobile  nitro 
group. 

In  our  tests,  we  have  used  the  apparatus  described  by  Kast  with 
a  stamp  surface  of  5  sq.  cm. ;  we  have  used  only  a  single  apparatus 
because  we  have  had  no  others  at  our  disposal.  We  have  operated 
at  a  temperature  of  19°  to  23°  ;6  in  order  to  be  sure  of  the  constancy 
in  temperature  of  the  stamps,  we  have  proceeded  as  follows:  Four 
stamps  were  employed  in  a  determined  order  and  washed  in  acetone, 
volatilized  rapidly,  and  then  permitted  to  remain  during  the  pre- 
vious operation.  The  purity  of  the  explosives  tested  was  the  same 
as  those  whose  stability  and  initial  explosion  temperature  were 
measured.  But  as  the  physical  state  has  an  influence  the  com- 

1  Wohler,  Zeitscltr.  f.  angew.  Chem.,  24,  2089  (1911). 

-  Van't  Hoff,  "Vorlesung  iiber  theor.  und  physikal.  Chem.,"  1900,  III,  95. 

3  Dupre,  "Mem.  des  Poudres  et  Salpetres,"  11,  94  (1901).     See  also  Brunswig,  "Ex- 
plosivstoffe,"  1909,    7-14. 

4  Will,  Ber.  d.  deutsch.  chem.  Ges.,  47,  704  (1914). 

5  On  this,  Will  has  not  published  information;  he  mentions  only  that  the  three  isomers 
have  almost  the  same  heat  of  combustion,  which  is  about  3660  calories. 

6  Because  of  the  bad  location  of  our  impact  machine  we  have  not  operated  between 
18°  and  20°  (Kast,  Zeitschr.f.  d.  ges.  Sell  less-  und  Sprengstoftw.,  4,  26-3  (1909),  or  between 
15°  to  20°  (Escales.  "Nitrosprengstoffe,"  Leipzig,  191."),  423). 


BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP       3 1 

pounds  were  formed  by  slow  and  tranquil  crystallization  which  has 
given,  in  nearly  all  cases,  hard  crystals  which  were  then  pulverized. 
Only  the  trinitroamidophenetol  and  the  trinitromethylnitramino- 
phenetol  have  failed  to  give  hard  crystals;  these  were  always  more 
or  less  elastic.  Finally,  the  pulverized  explosives  were  dried  during 
24  hours  over  fragments  of  potash.  We  have  preferred  potash 
to  the  usual  calcium  chloride  because  certain  of  these  explosives 
were  recrystallized  from  glacial  acetic  acid. 

For  the  tetranitrophenylmethylnitramine  we  have  made  a  final 
crystallization  in  benzene,  with  agitation,  for  the  crystals  obtained 
by  slow  crystallization  are  very  hard  and  their  pulverization  appears 
too  dangerous  on  account  of  the  great  sensibility  which  we  attribute 
to  this  body.  It  is  true  that  we  have  pulverized  this  compound 
under  a  glass  with  the  aid  of  a  horn  spatula,  but  we  have  not  sieved 
it  because  the  small  particles  agglutinate  into  boulets. 

Since  constancy  in  the  thickness  of  the  layer  of  explosive  is  of 
great  importance,  we  have  measured  the  materials  in  a  large  capsule 
containing  on  an  average,  when  used  for  tetryl,  about  42  mg.  It  is 
evident  that  the  quantities  of  the  different  materials  measured  in 
this  manner  will  not  be  the  same.  The  weights  are  given  for  each 
substance  tested  in  the  tables  which  follow.  After  having  obtained 
uniformity  in  the  degree  of  fineness  of  the  materials,  we  have  sieved 
them  through  a  sieve  of  1330  apertures  per  sq.  cm.,  with  a  diameter 
of  wire  of  0.105  mm.  Since  tetryl  appears  more  and  more  to  be 
accepted  as  a  standard,  we  have  taken  this  substance  as  the  standard 
of  comparison  and  we  have  determined  the  results  by  measurements 
repeated  each  day.  In  the  tables  which  follow  we  have  recorded 
these  values  beside  those  for  the  explosive  tested  the  same  day. 
The  determinations  of  all  of  these  substances  have  been  made  on 
two  different  days;  the  two  values  will  be  found  in  the  table. 

We  have  at  first  employed  in  our  experiments  a  weight  of  2  kg., 
but  since  for  about  8  explosives  the  maximum  height  of  fall  es- 
tablished for  this  weight  (60  cm. l]  is  not  sufficient,  for  these  explo- 
sives we  have  used  a  weight  of  10  kg.2  Following  Kast,  we  have 
determined  the  maximum  height  of  fall  for  which  there  is  no  explo- 
sion in  an  uninterrupted  series  of  6  trials,  and  the  minimum  height 
of  fall,  for  which  there  is  always  an  explosion,  with  an  uninterrupted 

1  We  wished  to  keep  to  the  maximum  height  which  Kast  states  was  followed  in  his 
researches. 

2  We  had  only  weights  of  2  and  10  kg.  at  our  disposal. 


32        BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP 


TABLE  II 
Weight  of  plunger  2  kg.     Temperature  19-23' 


NAME  OF  EXPLOSIVE 


MEAN 

QUANTITIES 

OF  SUB- 
STANCE IN 
CAPSULE 
IN  MG. 


MAX. 

HT. 

0  TO  6 

CM. 


MIN. 
HT. 

6  TO  I 

CM. 


MAX. 
HT. 

0  TO  6 

CM., 


STANDARD 

(TETRYL) 


MIN. 
HT-. 

6  TO  6 

CM. 


Trinitrotoluene 39 

Picric  acid 36 

Tetranitroaniline 39 

Tetranitroamidophenol 46 

Tetranitroamidoanisol 37 

Tetranitroamidophenetol 37 

Tetranitrometaphenylenediamine  ....  33 

Tetranitrophenylmethylnitramine ....  25 

Trinitromethylnitraminophenol 42 

Trinitromethylnitraminoanisol 39 

Trinitromethylnitraminophenetol  ....  34 

Aminotrinitrophenylmethylnitramine.  42 

2,4,6,3 '  ,4  ',6  '-Hexanitrodiphenylether.  39 

Hexanitrodiphenylsulphide 47 

Hexanitrodiphenylsulphone 38 

Trinitrodimethyldinitraminobenzene .  40 

Dipicrylamine 38 

2,4,6,2',3',4'-Hexanitrodiphenylamine  41 

Tetranitrophenol 40 


>60 

>60 

>60 

>60 

55 

54 

>60 

>60 

>60 

>60 

>60 

>60 

>60 

>60 

19 

19 

33 

30 

>60 

>60 

>60 

>60 

45 

43 

35 

32 

36 

39 

43 

43 

21 

26 

49 

49 

47 

44 

26 

28 


>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
36  > 
362 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
373 
36  4 
>60 


>60 

>60 

45s 

52« 


51 
49 

51 
49 
53 
51 
49 
49 
49 
49 
49 
49 
51 
50 
53 
51 
51 
50 
51 
51 
51 
51 
51 
51 
50 
53 
49 
51 
49 
51 
49 
51 
50 
53 
50 
53 
53 
51 


>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>60 
>'60 
>60 
>60 
>60 


1  and  2.     All  six  explosions  complete  with  flames. 

3  All  explosions  complete ;  only  four  with  flames. 

4  All  explosions  complete  with  flames. 

'and  6.     All  explosions  complete  with  flames,  very  strong  detonation  and  great  flame. 


BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP       33 


series  of  6  trials.1     All  these   results   are   recorded   in   Tables    II 
and  III. 

TABLE  III 
Weight  of  plunger  10  kg.     Temperature  19-24° 


NAME  OP  EXPLOSIVE 

MEAN 
QUANTITIES 
OP  SUB- 
STANCE IN 
CAPSULE 
IN  MG. 

MAX. 

HT. 
0  TO  6 
CM. 

MIN. 
HT. 
6  TO  6 
CM. 

MAX. 
HT. 
0  TO  6 
CM. 

STANDARD 

(TETRYL) 

MIN. 

HT. 

6  TO  6 

CM. 

Trinitrotoluene  

39' 

24 

24 

14 

24 

Picric  acid  

36 

24 
18 

24 
24 

14 
14 

24 
24 

Trinitroamidophenol  

46 

19 
24 

24 
24 

14 
14 

24 
24 

Trinitroamidoanisol  

37 

221 

24 

24 

24 

14 
14 

24 
24 

Trinitroamidophenetol  

37 

24 
24 

24 
24 

14 

14 

24 

24 

Trinitrometaphenylenediamine  

33 

24 

24 

24 

24 

14 

14 

24 
24 

Trinitromethylnitramlnoanisol  

39 

24 
15 

24 
24 

14 
14 

24 
24 

Trinitromethylnitraminophenetol  .  .  . 

34 

16 
19 
16 

24 
24 
24 

14 
14 
14 

24 
24 
24 

1  At  23  and  24  cm.  there  was  twice  produced  in  6  trials,  a  very  incomplete  explosion ; 
the  compounds  simply  inflamed. 

CONCLUSIONS 

a.  It  has  been  shown  repeatedly  that  Kast's  apparatus  and  meth- 
ods are  satisfactory  for  obtaining  precise  results.2 

b.  The  introduction  of  a  methylnitramino  or  a  fourth  nitro  group 
notably  augments  the   sensibility,  while  an  amino  group  lowers  it; 
one  may  compare  in  this  regard  the  following  compounds : 

Trinitrophenylmethylnitramine  and  trinitrodimethy  Idinitramino- 
benzene. 

Trinitrophenol  and  trinitromethylnitraminophenol. 
Trinitroaniline  and  aminotrinitrophenylmethylnitramine. 

1  In  the  table  these  heights  are  indicated  briefly  as  follows:     Maximum  height  from 
0  to  6.     Minimum  height  from  6  to  6. 

2  See  also  the  detailed  researches  of  Kast,  Zeitschr.f.  d.  ges.  Schiess-  und  Sprengstoffw., 
6,  7,  21,  67  (1911).     On  the  subjects  of  the  picrates  and  cresylates  and  trinitro  bodies, 
it  is  not  entirely  clear  why  Kast  tested  these  compounds  with  different  heights  of  fall 
when  he  had  previously  recommended  their  determination  by  "maximum  height  from 
0  to  6  and  minimum  height  from  6  to  6."    Ibid.,  4,  263  (1909).    We  have  not  encountered 
a  similar  condition  elsewhere. 


34        BRISA NT  NITRO  EXPLOSI VES:  VAN  D UIN  AND  VAN  LENNEP 

Trinitroaniline  and  tetranitroaniline. 

Trinitrophenol  and  tetranitrophenol. 

Trinitrophenylmethylnitramine  and  tetranitrophenylmethylni- 
tramine. 

Trinitrophenol  and  trinitroamidophenol. 

Tetranitroaniline  and  the  other  tetranitro  compounds. 

It  would  be  expected,  a  priori,  that  the  alkylation  of  a  phenol 
would  diminish  its  sensitiveness;  a  comparison  of  trinitromethyl- 
nitraminophenol  with  the  trinitromethylnitraminoanisol  and  phene- 
tol  shows  clearly  that  this  influence  is  great. 

In  addition  to  the  nature  of  the  group,  the  mobility  thus  intro- 
duced into  richly  substituted  nitro  compounds  has  also  its  influ- 
ence;1 the  mobility  increases  the  sensitiveness.  This  is  why  the 
aminonitrophenylmethylnitramine  is  more  sensitive  than  tetryl; 
the  amino  group  of  the  first  diminishes  its  sensitiveness.  More- 
over, the  methylnitramino  group  is  much  more  mobile  than  in  the 
tetryl  and  as  a  consequence  it  is  possible  to  replace  it  by  w-nitro- 
aniline  in  the  first  body,  while  such  is  not  the  case  for  tetryl.2 

c.  The  samples  of  dipicrylamine  and  2,4,6,2',3/,4'-hexanitrodi- 
phenylamine  show  that  the  replacement  of  a  fixed  nitro  group  by  a 
mobile  nitro  group  produces  a  remarkable  effect  upon  the  sensitive- 
ness.3     In     the      2,4,6,2/,3/,4/-hexamtrodiphenylamirie    the    nitro 
group  in  the  3  position  is  very  mobile,  as  shown  by  its  direct  reaction 
with  dimethylaniline. 

d.  The  data  found  in  the  literature  on  the  subject  of  certain  ex- 
plosives are  not  exact.    It  is  thus  that  Flurscheim4  in  the  following 
table  shows  that  tetranitroaniline  is  manifestly  less  sensitive  than 
tetryl : 

Weight  of  plunger,  5  kg. 


FIRST  SERIES 

SECOND  SERIES 

THIRD  SERIES 

Tetryl  

25  cm 

50  cm 

35  cm 

Tetranitroaniline  

45  cm 

W)  cm 

50  cm. 

Picric  acid  .  . 

35  cm. 

1  Van  Duin,  Rec.  trav.  chim.,  38,  89  (1919). 

2  Van  Duin,  loc.  cit. 

3  vSee  Will,  Ber.  d.  deutsch.  chem.  Ccs.,  47,  704  (1914). 

4  Fliirscheim,  Zeitschr.  f.  d.  ges.  Schiess-  und  Sprengslotjw.,  8,  186  (1913).     On  this 
subject  he  has  given  an  unacceptable  explanation  of  these  discordant  values  especially, 
but  little  confidence  can  be  placed  in  the  tests  of  the  plunger  and  the  difference  in  the 
quality  of  the  nitro  compounds.     We  believe  that  he  worked  each  time  with  different 
and  impure  material. 


BRISA NT  NITRO  EXPLOSI VES :  VAN  D UIN  AND  VAN  LENNEP       35 

Such  series,  for  which  it  is  evident  that  proper  precautions  have 
not  been  taken,  cannot  lead  to  any  conclusion.  The  author  shows, 
however,  that  the  sensitiveness  of  tetryl  and  of  tetranitroaniline 
for  mercury  fulminate  is  the  same  and  this  agrees  with  our  results.1 

Also  it  was  shown  that  2,4,6,3',4/,6/-hexanitrodiphenylether  is 
quite  insensititive;2  in  fact  the  sensitiveness  of  this  compound  is 
greater  than  that  of  tetryl. 

e.  Certain  of  the  explosives  studied,  the  tetranitrophenylmethyl- 
nitramine  and  the  trinitrodimethyldinitraminobenzene  ought  not 
to  be  included  in  the  class  of  nitro  explosives. 

In  1906,  Will8  classified  explosives  according  to  their  sensitiveness 
to  a  falling  weight  of  2  kg.  as  follows,  and  this  classification  is  still 
of  value:4 

1st  class. — Height  of  plunger  0  -  -  7  cm.  To  this  class  belong 
mercury  fulminate,  nitroglycerine,  some  picrates,  etc. 

2d  class. — Height  of  plunger  7  --  25  cm.  Includes  among  others 
the  dynamites. 

3d  class. — Height  of  plunger  26  —  100  cm.  Includes  among 
others  most  of  the  aromatic  nitro  compounds. 

4th  class. — Height  of  plunger  100  —  200  cm.  Includes  many 
quite  insensitive  nitro  compounds. 

As  we  have  demonstrated,  sensitiveness  increases  by  progressive 
substitution  of  nitro  and  methylnitramino  groups  in  the  benzene 
nucleus,  and  compounds  formed  by  such  substitutions  belong  to 
another  class  than  that  of  the  ordinary  nitro  explosives. 

Finally,  on  the  subject  of  the  use  of  modern  brisant  explosives 
our  previous  publications  should  be  consulted.5 
HEMBRUG,  ZAANDAM 

LABORATOIRE  DE  CHIMIE  DE  LA  FABRIQUE  DE  MUNITIONS, 
March,  1919. 

1  See  Bichel,  Gliickauf,  47,  1194  (1905). 

'2  Escales,  "Nitrosprengstoffe,"  82. 

3  Will,  Zeitschr.f.  d.  ges.  Schiess-  und  Sprengstotjw.,  1,  209  (1906). 

4  See  Marshall,  "Explosives,  etc.,"  1915,  345. 

4  Van  Duin  and  Brackmann,  Chem.  Weekl,  16,  501  (1919). 


University  of  California 

SOUTHERN  REGIONAL  LIBRARY  FACILITY 

405  Hilgard  Avenue,  Los  Angeles,  CA  90024-1388 

Return  this  material  to  the  library 

from  which  it  was  borrowed. 


1 


RECEIVED 

APR  2  4  1998 
SEL/EMS  LIBRAE 


Bulletin  of  the  National  Research  Council 


Volume  1 

Number  1.  The  national  importance  of  scientific  and  industrial  re- 
search. By  George  Ellery  Hale  and  others.  October,  1919.  Pages 
43.  Price  50  cents. 

Number  2.  Research  laboratories  in  industrial  establishments  of  the 
United  States  of  America.  Compiled  by  Alfred  D.  Flinn.  March, 
1920.  Pages  85.  Price  $1.00. 

Number  3.  Periodical  bibliographies  and  abstracts  for  the  scientific 
and  technological  journals  of  the  world.  Compiled  by  R.  Cobb. 
June,  1920.  Pages  24.  Price  40  cents. 

Number  4.  North  American  forest  research.  Compiled  by  the  Com- 
mittee on  American  Forest  Research,  Society  of  American  Foresters. 
August,  1920.  Pages  146.  Price  $2.00. 


By    Edwin  P.  Adams.     October, 


Number  5.     The   quantum   theory. 
1920.     Pages  81.     Price  $1.00. 

Number  6.  Data  relating  to  X-ray  spectra.  By  William  Duane. 
November,  1920.  Pages  26.  Price  50  cents. 

Number  7.  Intensity  of  emission  of  X-rays  and  their  reflection  from 
crystals.  By  Bergen  Davis.  Problems  of  X-ray  emission.  By  David 
L.'Webster.  December,  1920.  Pages  47.  Price  60  cents. 

Number  8.  Intellectual  and  educational  status  of  the  medical  pro- 
fession as  represented  in  the  United  States  Army.  By  Margaret  V. 
Cobb  and  Robert  M.  Yerkes.  February,  1921 .  Pages  76.  Price  $1 .00. 


Volume  2 

Number  9.  Funds  available  in  the  United  States  of  America  for 
the  encouragement  of  scientific  research.  Compiled  by  Callie  Hull. 
March,  1921.  Pages  81.  Price  $1.00. 

Number  10.  Report  on  photo-electricity  including  ionizing  and  radiating 
potentials  and  related  effects.  By  Arthur  Llewelyn  Hughes.  April, 
1921.  Pages  87.  Price  $1.00. 


Reprint  and  Circular  Series  of  the  National 
Research  Council 

Number  1.  Report  of  the  Patent  Committee  of  the  National  Research 
Council.  Presented  for  the  Committee  by  L.  H.  Baekeland,  Acting 
Chairman.  February,  1919.  Pages  24.  Price  30  cents. 

Number  2.  Report  of  the  Psychology  Committee  of  the  National 
Research  Council.  Presented  for  the  Committee  by  Robert  M. 
Yerkes,  Chairman.  March,  1919.  Pages  51.  Price  60  cents. 

Number  3.  Refractory  materials  as  a  field  for  research.  By  Edward 
W.  Washburn.  January,  1919.  Pages  24.  Price  30  cents. 

Number  4.  Industrial  research.  By  F.  B.  Jewett.  1918.  Pages 
16.  Price  25  cents. 

Number  5.  Some  problems  of  sidereal  astronomy.  By  Henry  N. 
Russell.  October,  1919.  Pages  26.  Price  30  cents. 

Number  6.  The  development  of  research  in  the  United  States.  By 
James  Rowland  Angell.  November,  1919.  Pages  13.  Price  25 
cents. 

Number  7.  The  larger  opportunities  for  research  on  the  relations  of 
solar  and  terrestrial  radiation.  By  C.  G.  Abbot.  February,  1920. 
Pages  14.  Price  20  cents. 

Number  8.  Science  and  the  industries.  By  John  J.  Carty.  February, 
1920.  Pages  16.  Price  25  cents. 

Number  9.  A  reading  list  on  scientific  and  industrial  research  and  the 
service  of  the  chemist  to  industry.  By  Clarence  Jay  West.  April, 
1920.  Pages  45.  Price  50  cents. 

Number  10.  Report  on  the  organization  of  the  International  Astronomi- 
cal Union.  Presented  for  the  American  Section,  International 
Astronomical  Union.  By  W.  W.  Campbell,  Chairman,  and  Joel 
Stebbins,  Secretary.  June,  1920.  Pages  48.  Price  50  cents. 

Number  11.  A  survey  of  research  problems  in  geophysics.  Prepared 
by  Chairmen  of  Sections  of  the  American  Geophysical  Union.  Oc- 
tober, 1920.  Pages  57.  Price  60  cents. 

Number  12.  Doctorates  conferred  in  the  sciences  in  1920  by  American 
universities.  Compiled  by  Callie  Hull.  November,  1920.  Pages  9. 
Price  20  cents. 

Number  13.  Research  problems  in  colloid  chemistry.  By  Wilder  D. 
Bancroft.  April,  1921.  Pages  54.  Price  50  cents. 

Number  14.  The  relation  of  pure  science  to  industrial  research.  BT 
John  J.  Carty.  October,  1916.  Pages  16.  Price  20  cents. 

Number  15.  Researches  on  modern  brisant  nitro  explosives.  By  C.  F 
van  Duin  and  B.  C.  Roeters  van  Ivennep.  Translated  by  Charles  F 
Munroe.  February,  1920.  Pages  35.  Price  50  cents. 


